National Park Service Will Cite AWD Drivers for Driving on 4WD-Only Trails

https://jalopnik.com/national-park-service-will-cite-drivers-of-awd-cars-for-1851617315

by rntn • 2 years ago

131 267 2 years ago

COGlory2• 2 years ago

While there are rare situations where locking differentials are meaningful, having been in many hair raising off-road situations, including a real life or death one, I'd much rather have AWD and clearance, than 4WD and no clearance.

That is to say, I'm not convinced by the article's hypothesis about locking diffs. It's extremely rare to need to deploy those: beached, or slow starts up vertical surfaces like boulders. An AWD vehicle with good tires and good clearance is really quite good. Bonus points if you don't care about wrecking it.

NDizzle• 2 years ago

What 4wd vehicle doesn’t have good ground clearance?!

tom_• 2 years ago

First generation Subaru Justy.

jofer6• 2 years ago

Most stock pickups, actually. You'd be surprised how low the clearance is on a stock f150 without the various off-road packages. I.e. you can easily have a pickup with basic 4wd but only 8 inches of ground clearance. That's technically "high clearance", but not by much, and the poor approach, departure, and break over angles make it tough too.

ezfe• 2 years ago

Subaru Impreza has less than 8 inches of ground clearance, which is the threshold they use in the link.

ghaff3• 2 years ago

Depending on your definition of "good," probably most of them. While I have been guilty of taking questionable AWD rentals on questionable roads in places like Death Valley when younger, you really want properly-equipped Jeep Rubicons and the like that you're not going to get from the average car rental place.

COGlory2• 2 years ago

None, which is my point. I'm trying to say I suspect it's ground clearance, not locking differentials that matters on these roads.

kube-system4• 2 years ago

Suzuki X-90 ?

briankelly2• 2 years ago

4WD and no clearance

I think I've only really seen this as a Honda Element - otherwise I'm not sure it meaningfully exists. The reality with most AWD cars is that their important guts are hanging lower compared to 4WD trucks even when the paper ground clearance is similar.

My previous car was AWD and I have a 4WD SUV now largely for off road performance, and there's no question 4WD (particularly 4LO) is much better at getting unstuck in trail conditions. The AWD is definitely superior for icy pavement in the cold months though.

Bonus points if you don't care about wrecking it

This was actually what mainly pushed me over to the 4WD side instead of something like the Forester. The crossovers can actually get you to a lot of places but they do get thrashed if you do it enough. They are still more geared for pavement use but, if you're wrecking your suspension off road, the on road performance isn't gonna be great either.

ADSSDA2• 2 years ago

I think I've only really seen this as a Honda Element

What Honda element had 4wd? As far as I'm aware they were all (a pretty bad) AWD system.

soganess• 2 years ago

I'm working from memory here, but I believe early 90s Audi "quattro"s (like the 100) had the feature. That said, I think we are very much in "the exception that proves the rule" territory.

toast0• 2 years ago

I think I've only really seen this as a Honda Element - otherwise I'm not sure it meaningfully exists.

Maybe it's not meaningful, but vans in the 80s and 90s were often offered with optional 4x4, sometimes with a locking differential. An unmodified Astro or Aerostar doesn't have a whole lot of ground clearance, but could fit the definition of 4wd if properly optioned and probably wouldn't be suitable for these trails unless it gets some aftermarket help.

Of course, few of these are running anymore. 4x4 kei vans can get pretty serious too, but not a lot running on US national park fire roads.

Zandikar• 2 years ago

That is to say, I'm not convinced by the article's hypothesis about locking diffs.

I'm not an offroader, but I did own a vehicle without a locking diff, that I later upgraded to having a locking diff (slapped a G80 on the rear of an 80's GMC Sierra) and that made a huge difference even on pavement in inclement weather. Granted, that was a RWD pickup with very little weight (typically) over the drive wheels. I'd honestly be shocked if the impact was minimal in truly offroad conditions. Granted, that's RWD which is even less than AWD or 4WD, so by no means apples to apples comparison there, just my 2 cents.

That said, this isn't a binary thing (locking vs open). There's a wide variety of AWD technology out there, and I could nerd out on the specifics, but at the end of the day, some are very limited in their ability to send power to one set of wheels vs the other, and may not have locking/limited slip diffs at all, and just use brakes to prevent wheel spin. I will say, Subaru (especially the higher/sportier trims like WRX/STi) can often hang and even shame some 4WD vehicles in some conditions. There's no shortage of videos of Subarus helping a 4WD out of a jam, or completing a course they could not, but how much of that is a function of their specific AWD tech and limited slip diffs vs proper tires and lighter weight and any number of things is a matter of debate that I'm not qualified to weigh in on. Again, am a gearhead, but not an offroader.

So I suspect it's not so much the Park saying "Subaru/AWD can't cut it" but rather, keeping track of which years, brands, models, trims, and/or potential optional equipment does cut it is a much more massive headache to keep track of and verify than just saying "4WD yes, everything else no", and I can't really fault them for that.

pandaman• 2 years ago

I am not an off-roader by any stretch of imagination, but I figure the AWD works like single axle drive with a simple diff on each axle i.e. if one wheel has no traction then all torque goes to that wheel and zero goes to the opposite one. I once got stuck on pretty solid pavement in a RWD car when one rear wheel hanged off a curb and lost traction, after that the car could not move as the only wheel getting torque was the one hanging off the ground. I figure the other axle would still get torque on an AWD as they usually have some kind of limited slip mid diff effect from whatever scheme they use to distribute torque between axles, but if you hanged out a wheel on each axle then an AWD vehicle would become stuck too?

davidbanham6• 2 years ago

Locking differentials are very useful in particularly challenging terrain. Think step rough rock climbs or soft sand. For punting along an average fire trail or dirt road, though, it’s clearance, strong tyres and suspension travel that’s more important.

A Subaru has none of the above. They make great cars, but they’re not an off road vehicle.

quasse2• 2 years ago

I say this as a Jeep owner; it's ridiculous to claim that Subarus are not appropriate for punting along fire trails. The average obstacle on fire trails in the PNW is mud or large potholes, both of which a Subaru is perfectly appropriate for. A Crosstrek has 8.7in of ground clearance which is plenty compared to say, a Prius.

That being said, the trail from the linked article is not an average fire road. They have genuine rock hazards, steep slick rock climbs and descents, and deep sand. I'm sure the national park service is extremely tired of people getting stuck and setting off their emergency beacons because they drove inappropriate vehicles into the park.

barkingcat3• 2 years ago

the previous poster didn't say that subarus are not appropriate for fire trails, it's saying that Subaru's are not off road vehicles for "particularly challenging terrain", as in "Think step rough rock climbs or soft sand."

What it does say is that for fire trails, "clearance, strong tyres and suspension travel" are more important, which the Subaru does quality for.

davidbanham6• 2 years ago

If you've driven the trail before, know what the weather has been like recently, and have some info to suggest that the trail remains in good condition then absolutely!

Thing is, there are great fire trails and awful fire trails. They don't consistently stay one or the other, either. Some of the trails near me have just been re-done and I'd happily drive in a Subaru BRZ. Others I wouldn't go down in our Isuzu FTS-800.

nullc• 2 years ago

There is rock climbing on this particular road, not super severe but something that most passenger cars would be easily hung on.

devoutsalsa• 2 years ago

I drove a Toyota Prius into some really ridiculous terrain. It was all I had and I really wanted to see some places that weren’t accessible by paved roads.

Here’s what I Learned about driving a 2WD car into questionable situations:

- driving up particularly steeps roads isn’t going to happen because the gearing doesn’t go low enough on the car, and the car won’t have enough power to struggle up the steep grade

- the biggest challenge on any road is ground clearance, so it’s hard to drive over big rocks, rises/drips in elevation, and generally uneven surfaces

- good luck driving through significant mud and water

So if you’re driving along a fire road when it isn’t raining, as long is it’s not too steep, raining, and the rocks aren’t too big, and car with decent tires can probably do it, especially a Subaru.

partitioned• 2 years ago

My friend has a subaru that he regularly takes on stuff that always impresses the truck and jeep riders. This includes soft sand on dunes, straight up the sides of leaf covered hills, through high rivers with rock bottoms. I think he has lifted it slightly but just about an inch or so with new performance shocks.

chung81232• 2 years ago

I wouldn't say 4WD vs AWD is the best filter but if that is all they can come up with I guess it works.

Some Audi's have locking differentials and they are AWD.

morganw• 2 years ago

Audi's with Torsens only lock front-to-back (but then so do a lot of 4WD vehicles). They use brakes to stop slipping wheels so the other side will get torque. A long time ago, they had lockers for the rear for low speed use.

rasz2• 2 years ago

Locking differential is a fix for poor suspension travel.

If your car can do this

https://wranglertjforum.com/threads/how-much-up-travel-do-yo...

then there is no point locking the diff, wheels will be touching ground at all times, no slippage, full traction.

kube-system4• 2 years ago

Tires can slip while in contact with the ground, as well.

gorgoiler• 2 years ago

I have say I’ve needed to use difflock on the Defender (another solid axle vehicle excellent at maintaining ground clearance) more times for mud than for ditch traversal.

alamortsubite5• 2 years ago

No, this is only true with equal traction at each wheel, which quite often isn't the case (mud, snow, ice, etc.). Locking diffs are very useful offroad.

chubs2• 2 years ago

I have a new Tiguan. It’s supposed to be AWD. In reality though, even when in off-road mode, it’s basically front-wheel-drive as evidenced by the fronts spinning when you accelerate hard into a gap in traffic. Most cars that use a Haldex oem for their awd act similarly.

OrigamiPastrami2• 2 years ago

The neat thing about the Haldex is that with just a software tune you can substantially improve the performance of it. The hardware is actually far more capable than you'd ever know with the enormous amount of slack that's programmed into it from the manufacturers. Obviously this voids your warranty, but it's a fairly low-risk modification.

chubs2• 2 years ago

Ok I’m interested… how is this doable?

SkyPuncher13• 2 years ago

Do you have adjustable drive modes?

When I put my car into sport mode, it does nearly 50/50 power application. When it’s in normal or eco, it will put 80% of the load on the front tires, then only increase rear tire load as needed.

williamstein• 2 years ago

"Up to six months imprisonment" for repeat offenders.

nofunsir6• 2 years ago

Whatever happened to cruel and unusual?

drewg123• 2 years ago

I wonder what this even means in the context of EVs? Eg, some vehicles have a motor per wheel...

op00to2• 2 years ago

The actual letter says “High clearance 4WD”. There’s more to off-roading than traction.

leoh• 2 years ago

No, off-roading is about having the right equipment that doesn’t cause other people problems or problems that you regret. If I’m on a well-graded gravel road, it should be fine to take a Ferrari on it without stupid rules getting in the way.

dag11• 2 years ago

What is considered "high"?

The Rivian R1T's clearance goes up to 14.9 inches, and has a motor per wheel. Does it count?

mikestew• 2 years ago

"Some", which is what, just Rivian? I wouldn't take our dual-motor Hyundai Ioniq 5 down anything more technical than a forest road, if only because of its (IIRC) 7 inches of ground clearance. And I imagine the AWD software is tuned to icy suburban streets, not something like this trail. Best I can tell, the AWD is supposed to get you to the ski slopes, not down the Rubicon.

ADSSDA2• 2 years ago

As pretty much anyone who offroads knows, AWD vehicles absolutely tear up the trails vs a proper 4wd with lockers, since AWD relies on detecting tirespin (ie, destroying trail) to determine when it needs to activate.

londons_explore3• 2 years ago

It's really just poor sensors and software.

AWD can theoretically work far better than a 4WD with diff locks, because it can simulate, based on the steering wheel angle, the exact speed each wheel should turn, and 'lock' each wheel to that speed giving zero slippage.

Just a shame that the sensor -> computer -> actuator feedback loop seems to be 200 milliseconds or more, so AWD vehicles just end up having different wheels slip semi-at-random till that wheel gets the brakes activated 200ms later.

jofer6• 2 years ago

AWD has come a long way in that regard in the last few years. It's still highly variable from manufacturer to manufacturer, but systems that use internal clutches alongside brakes (and not only brakes) to control wheel movement + tight feedback loops can really do a great job of minimizing wheel spin.

They get a lot of hate, but the bronco sport has the best AWD system I've driven to date in that regard.

And with that said, it is still the type of thing the Park Service would rightfully cite as not a proper 4wd. 9ish inches of clearance is not much, and the lack of a low range will bite you. I've taken mine on plenty of milder 4wd only trails in parks (e.g. black gap in big bend plus tons and tons of forest service roads), but I'm certainly not going to do elephant hill in canyonlands with it. That's what the dedicated off-road rig is for.

There are "4wd only" trails in national parks that high clearance AWD is fine on. The rangers will tell you which ones those are.

Canyonlands is a different beast than most national parks. Canyonlands has some very gnarly trails open if you have a permit. Lookup dollhouse sometime. Beautiful, but insanely technical. Elephant hill is better known and a bit milder.

Zak2• 2 years ago

Most AWD systems do not have the ability to vector torque like that. They're usually based on mechanical limited-slip differentials that require some amount of slip before they partially lock, and sometimes the limited slip is only between front and rear, not left and right. There are different types, with some requiring a lot of slip before they lock up and others requiring little.

Limited slip differentials cost more than open differentials. Limited-slip differentials that lock up quickly cost more than those that allow a lot of wheelspin. Electronically-controlled torque-vectoring differentials cost yet more.

The system you describe seems to meet the NPS definition of 4WD someone linked elsewhere: "a means to mechanically power both front and rear wheels at the same time", though I wonder if there might be some more technical regulation with specific requirements. I agree that sort of thing could work well for off-road use.

SkyPuncher13• 2 years ago

It’s not just sensors. It’s mainly to avoid it falsely applying itself. In my opinion, that is far more dangerous because it’s wildly unpredictable when it will work as expected vs when it toque vector.

I can get the torque vectoring to do some weird things, kind the right conditions on my car. It’s okay because I’m intentionally pushing the limits, but I absolutely would not want the vectoring to kick in when I’m not expecting it. Towing on packed snow/ice is not the place you want to learn your wheels suddenly decided to react dramatically differently.

alamortsubite5• 2 years ago

Just as bad are heavy vehicles, which is pretty much everything marketed as "4WD" these days.

olliej2• 2 years ago

I still dont understand the difference between 4wd and awd, but the article spends more or less the entire time talking about locking and limited slip differentials and how AWD generally don’t have them which is “why they’re not allowed”, while also acknowledging that just being 4wd doesn’t mean there’s any kind of diff lock either.

If the actual reason ia the difference in how the diff is locked, then access should be restricted on the basis of that, not on the mechanism the wheels are driven.

I assume that the actual reason for the 4wd only rule is because there is a real difference in how they work?

barkingcat3• 2 years ago

This article says a bit about the differences:

https://www.caranddriver.com/features/a27630736/awd-vs-4wd/

The primary reason there's a 4WD vs AWD distinction is the ability to lock the differentials, and that determines the mechanisms that the wheels are driven by.

And that's why they use those terms in a prescriptive law context.

to simplify:

AWD -> power gets to all wheels (driven wheels) but wheels are usually allowed to spin at different speeds to facilitate pavement driving and turning.

4WD -> power gets to all wheels, but there is a locking mechanism that locks all wheels so they all turn at the same speed - if you know the physics of turning objects, it means turning while underway is either impossible or damaging to the drivetrain. This is however, useful in mud or rock, or challenging terrain. When on mud or rock or whatnot, you turn, move a bit, stop, check, turn a bit, move, stop, check, turn a bit, movie, stop, etc. So the fact that all wheels turn at the same time is an advantage.

The reason some 4WD don't have a "differential lock" is that it's fused by bare metal - it doesn't need a lock because it's welded together, so no lock needed!

The car and driver article gives an easy test: if the car manual tells you "this is bad for road driving" - that's 4WD.

you might think "well 4WD is terribly useless for regular driving" and you would be entirely correct. That's why most 4WD cars incorporate both modes of driving mechanisms so they can switch.

You can tell apart a permanent 4WD / full time rock climber by the owner needing to use a trailer to move the vehicle instead of driving it over the highway, usually they use a pickup truck or SUV with a regular drivetrain to haul gear and pull the trailer with the 4WD vehicle to the trailhead, unload, then go into places like Death Valley Back Country or Moab with the 4WD vehicle.

loeg4• 2 years ago

There are many 4WD vehicles that don't have locking or even limited slip diffs, though.

4WD -> power gets to all wheels, but there is a locking mechanism that locks all wheels so they all turn at the same speed

This isn't universally true of 4WD vehicles.

E.g., https://www.reddit.com/r/overlanding/comments/61yyam/4x4_wit... or https://www.quora.com/Do-all-4WDs-have-lockers

JumpCrisscross• 2 years ago

but wheels are usually allowed to spin at different speeds to facilitate pavement driving and turning

To drive home why NPS cares about this, the way the car detects how fast the wheel should spin is by detecting slippage. But every time that happens, you're shredding up the road. That turns AWD vehicles into pothole machines.

I drive a Subaru and I drive it off road. I would feel comfortable driving it in most off-road conditions, from a safety perspective, but I won't because I'm fucking up the trail.

acdha2• 2 years ago

I’d add that from the park service’s perspective this is pretty simple. They don’t want to have people getting stuck in the backcountry or damaging trails, and as an agency with limited staffing, millions of visitors, and huge territory to protect it’s understandable that they do not want some complicated argument with every wannabe rules lawyer who thinks they can drive like they saw in the commercial. “Only 4WD” is a policy that doesn’t require training thousands of rangers around the country about which models are considered acceptable.

3np2• 2 years ago

4WD -> power gets to all wheels, but there is a locking mechanism that locks all wheels so they all turn at the same speed - if you know the physics of turning objects, it means turning while underway is either impossible or damaging to the drivetrain.

Is my understanding of your usage of "underway" right if you're saying that the only recommended and safe way to use the steering wheel on a 4WD is when at standstill? That you can't/shouldn't turn at all when in motion?

loeg4• 2 years ago

I think you're correct -- there's not any functional benefit to 4WD (vs AWD) without locked diffs. The signage should probably demand locked diffs.

chung81232• 2 years ago

Plus AWD can have locking differentials.

alamortsubite5• 2 years ago

"4WD" implies transfer case, rather than center diff.

hnav• 2 years ago

Serious offroad vehicles traditionally don't have a center diff and instead let you lock the axles together by putting the transfer case into 4hi or 4lo (for extra torque multiplication) which means that you need to lift at least a front and a rear wheel off the ground before getting stuck. Front/rear locking diffs further reduce the odds of getting stuck. Crossovers typically have a FWD drivetrain with an appendage that sends power to a rear axle that contains an electromechanically actuated or viscous coupling which is very similar. The coupling is actually in a way similar to a transfer case but takes wheelspin to kick in which sucks offroad. Then some trucks and sporty cars use an electromechanically actuated transfer case that sends power forward. The Mercedes G-class and Humvee have a center diff so are technically full time AWD but then they also have a reduction gear as well. Basically it's hard to classify vehicles' offroad capability so the copout is using 4WD to mean real offroad and AWD to mean "get you unstuck from a couple inches of snow".

dboreham• 2 years ago

Quick note from a place with feet of snow to say that AWD vehicles work well here. People either drive trucks or Subarus and I don't see more of one kind stuck in snow than the other. Obviously winter tires required.

SkyPuncher13• 2 years ago

4WD drive means all tires spin at the exact same speed, no matter what. AWD drive means each tire can rotate at a different speed. Tires with less grip will spin faster. Notably, if a tire on an AWD car is in the air, only that tire will spin. You won’t move anywhere because all of the force is expelled through the free wheeling tire.

4WD solves this issue by essentially locking everything together. Great for unsticking yourself, but terrible for every day driving. Things like turning into a parking spot can cause binding since wheels on the outside of the turn need to travel a longer distance than those on the inside of a turn

olliej2• 2 years ago

Ah, so AWD vs 4WD is _definitionally_ the presence or lack of some form of locking differential?

e.g if I were to take an AWD and weld the diff it would be 4WD (and not be too fun for daily driving)?

aranchelk• 2 years ago

4WD drive means all tires spin at the exact same speed, no matter what.

Make sure you only drive in a straight line.

dingaling• 2 years ago

Notably, if a tire on an AWD car is in the air, only that tire will spin

On the contrary, here's a demonstration of the opposite. Subaru AWD, three wheels without grip, power goes to the wheel with grip.

https://m.youtube.com/watch?v=mryGnENTsoI

i_am_jl• 2 years ago

Not sure about this park, but elsewhere the NPS has made this distinction clear.

Death Valley's map makes clear that a high clearance crossover, high clearance 2WD or high clearance AWD vehicle is one class, and 4WD vehicles are another. See page 2:

https://www.nps.gov/deva/planyourvisit/upload/508-Backcountr...

EDIT: https://www.nps.gov/cany/planyourvisit/maps.htm has a whole lot of maps for the Canyonlands and none of them make this distinction, maybe this isn't as apparent at that park.

SkyPuncher13• 2 years ago

It was very clearly defined, but finding the definition would require you to go looking for it.

rocqua• 2 years ago

Notably, this marks a 4WD as having a low gearing case, ot says nothing about locked differentials.

ghaff3• 2 years ago

The Death Valley one seems reasonable--if a bit conservative, which is appropriate. And high clearance seems an appropriate distinction--which the rangers will make as well. It's probably also worth noting that for places like the Racetrack having appropriate tires (and full-size spares) is important as well. I wouldn't have an issue driving there on my own but I wouldn't probably do it in a random rental.

ryandrake• 2 years ago

It's good that amongst the know-it-all Reddit responses typical to these kinds of education threads, the OP learned something about his or her car, and came out of the thread with a better knowledge of the differences between 4WD and AWD. One of the Redditors summed up the stupidity of these marketing terms:

    All Wheel Drive? Cool. There are four wheels. All of them means four.

I'm sure many people's knowledge of their car ends there. The terms 4WD and AWD are as misleading as USB Full Speed vs. USB High Speed (quick, tell me which one is faster without looking it up?)

jrs235• 2 years ago

AWD means that all the wheels receive power from the power train. Most AWD will stop providing power to a wheel if it loses traction (spins). This is because they have an unlocked differential. 4WD typically means all four wheels can receive power from the power train and can be locked so that that will not lose power if they spin.

falcolas• 2 years ago

AWD means that all the wheels receive power from the power train.

I used to think that, until my car (Dodge Charger) with AWD had its tail swing out on ice. Basically, AWD for that vehicle meant "Rear Wheel Drive until it slips," at which point the front wheels would receive power.

Same with my Toyota Prius, though it was FWD until it slipped, then the rear wheels kicked in. Even my AWD EV with dedicated motors doesn't have them all active all the time.

The Subaru is the only AWD vehicle I've owned which was full time 4 wheel drive.

bryanlarsen2• 2 years ago

Not all 4WD systems have locking differential's.

nkurz• 2 years ago

Since the original citation was for a Subaru, it made me wonder how Subaru's X-Mode actually works. It says, among other things:

X-MODE in Subaru vehicles is specifically engineered to push through tough conditions like snow and mud. By adjusting the throttle response and controlling the transmission, it ensures that power is distributed effectively to the wheels, reducing slip and enhancing grip.

https://www.subaru.com/vehicle-info/articles/what-is-subaru-...

Does anyone know what it actually does and how well it does it?

kube-system4• 2 years ago

If a wheel spins on an axle with an open differential, mechanically speaking, it receives all the power, being that it is the path of least resistance. That's a problem because the remaining wheels are the only useful ones for propelling the vehicle, but they stop receiving power. The reason power may be cut is a traction control system response to this slipping, not the mechanical drivetrain configuration itself. Depending on the vehicle, this may be done by cutting power at the engine, or by braking the individual wheel that is spinning, or both.

A locking differential distributes the power evenly between both sides, all of the time.

Limited-slip differentials do something in between the above two, depending on the type.

carabiner2• 2 years ago

No, locking diffs are not standard with 4WD. Tacomas have 4WD without locking diffs. This guy on Quora claims that 99% of 4WD vehicles are open differential: https://www.quora.com/Do-all-4WDs-have-lockers/answer/Glenn-...

londons_explore3• 2 years ago

The funny thing is, I think (nearly) all cars, with minor changes to the ABS unit, could have the hardware necessary for brake based torque vectoring within the ABS unit.

But, due to the ABS unit software being contracted out to a different company, it only is used for ABS and cannot act to make the car have a virtual diff lock, unless the car manufacturer wants to pay Bosch the extra $$$ for different software.

fingerlocks2• 2 years ago

Every AWD vehicle I’m familiar with has either a mechanical LSD (Ford, VW, Audi, early Subaru) or uses torque vectoring (late Subaru, Tesla).

If most AWDs have open diffs, who makes them? Honda and Kia?

bigstrat2003• 2 years ago

I certainly had no idea until this very thread that there might be any sort of difference. Like that Reddit user, I (quite reasonably) concluded that AWD and 4WD were the same thing since a car has four wheels.

Moru• 2 years ago

If it would be the same thing, they would all use the 4WD term that has been a thing since a long time.

diego_sandoval• 2 years ago

a car has four wheels.

Most cars at least :^)

Dalewyn6• 2 years ago

since a car has four wheels.

Some cars have only three.

https://en.wikipedia.org/wiki/Three-wheeler

SkyPuncher13• 2 years ago

I think this is a bit dismissive.

The rules regulating this clearly defined what was considered an appropriate vehicle and explicitly called out that AWD vehicles are not considered 4WD.

I will admit, the rule was not obviously posted, but knowing the rules is part of adventuring in public land like this.

Dalewyn6• 2 years ago

The terms 4WD and AWD are as misleading as USB Full Speed vs. USB High Speed (quick, tell me which one is faster without looking it up?)

Neither, because you're gonna stick it into a USB port.

vbezhenar• 2 years ago

USB Full Speed vs. USB High Speed (quick, tell me which one is faster without looking it up?)

I'm implementing USB protocol right now and those terms are PITA for me, I always mess them up. And next protocol I think called USB Super Speed, and next is Enhanced Super Speed. Those people in USB committee are really making fun of their work.

adrr• 2 years ago

Whats the difference between AWD and 4WD? Luxury SUVS are AWD and have transfer cases with locking diffs. G Wagons, Range rovers, Cayennes. The luxury crossovers have limited slip diffs and brake torque vectoring.

Edit: Not sure why i am getting downvoted. Here are the specs to a G Wagon. AWD with front and rear diff locks.

https://www.caranddriver.com/mercedes-benz/g-class/specs

SkyPuncher13• 2 years ago

G wagon is a proper 4WD vehicle. It might be able to drive in AWD modes, but it has proper diffs to do it.

There are loads of exceptions, but generally AWD vehicles have weaker or non-existent locking diffs. For example, I believe my AWD vehicle simulates locking diffs with clutch plates. Those clutches can and do slip. They’re effective at keeping the wheels “mostly locked” but not true 4WD.

Further, most of the brake based torque vectoring required “slip detection” that’s only possible when a wheel spins. These systems aren’t really perfect in actually locking out motion on a free wheel. They kind of have to let them slip from time to time to check condition. These systems also tend to allow a lot of spin before they kick in - that years up roads.

avar3• 2 years ago

With reference to previous absurd but technically correct interpretations of US national park rules[1] I'd like to suggest a way to comply with the rule in question [2], which states:

    High clearance four-wheel drive
    is required on motor vehicles
    travelling on [...]

Take a 2WD vehicle, then bolt an extra set of wheels onto the drive axle (the tires are apparently optional).

The vehicle would still need to be high-clearance.

Or, if you're feeling really adventurous, just glue a set of LEGO wheels to the center of the hub. Those wheels would demonstrably have a high clearance, and comply with the rule as written.

1. https://news.ycombinator.com/item?id=36453856

2. https://www.nps.gov/cany/learn/management/compendium.htm

metaphor• 2 years ago

Play stupid games, win stupid prizes.

Definitions:
High Clearance Four-Wheel-Drive (4WD) Vehicles
A Jeep, sport utility vehicle (SUV), or truck type with at least 15-inch tire rims and at least eight inches of clearance from the lowest point of the frame, body, suspension, or differential to the ground. Four wheel drive vehicles have a driveshaft that can directly power each wheel at the same time and a transfer case that can shift between powering two wheel or four wheels in low or high gear. All wheel drive (AWD) vehicles do not meet this definition.

avar3• 2 years ago

Just in case it's unclear, I'm not being serious here.

Still, it seems to me that the wording still allows for some rules lawyering.

When they say "directly power each wheel" they clearly mean the four wheels attached to the OEM axles.

But I think their wording is open to arguing that it's any four "wheels" of your choosing, and now that your drive axle has two wheels on each side...

The rest of the wording allows you to flip between arguing on the basis of your now-four wheel drive axle and the stock axle. After all, they're not saying "those two wheel or four wheels". Different sets of four wheels on your now six wheel car should satisfy all the criteria.

However, the mention of a transfer case is a showstopper. I shouldn't have mentioned 2WD.

But given the above contortions e.g. a BMW X5 with 216mm (8.7 inches) of clearance should qualify.

The manufacturer obstinately insists that it's not an AWD, but "xDrive". The gear ratio of the AT even is so low that you can idle at a standstill while in gear!

olalonde2• 2 years ago

Stupid question but why does the National Park Service care? I can't imagine people just abandon their cars when they get stuck?

kccqzy• 2 years ago

Creating less work for park rangers. If people drive unsuitable vehicles and get stuck, they will call emergency. That's independent of whether they abandon their cars.

akerl_• 2 years ago

No, they don't abandon them: they call for help and require both government and commercial assistance to get their cars unstuck.

davidbanham6• 2 years ago

Recovering a car from a remote area can be a big job. Not only do you need a vehicle capable of getting into and out of the spot where the first car got stuck, it might need to do so while also carrying the first car.

Dragging the first car to where you can get it on to the recovery vehicle can cause significant damage to the trail. Repairing that can be a big job when you can't just drive a tip truck full of sand/gravel/rocks to the spot. It's not at all outlandish for the consequences of a stuck Subaru to pretty quickly run to "We need to contract a high lift capacity helicopter for a few days to fly in a half tonne of gravel and a repair crew".

And then there's the fact that to some degree, you're endangering the people who need to come get you.

acdha2• 2 years ago

And then there's the fact that to some degree, you're endangering the people who need to come get you.

This is especially true because the same kind of people who will drive somewhere out of their league are more likely to also be doing so in bad conditions with inadequate preparation so the rescue team might be rushing at night, in adverse weather, etc. A couple of people I knew who went hiking or mountain biking in the BLM land east of San Diego had stories about sharing food and water with people who’d only packed driving treats and forgot that SUVs can get stuck pretty easily no matter what the ads showed.

nofunsir6• 2 years ago

Won't somebody think of the trails!? We should all stay home to preserve the trails so that some unknown generation at some unknown point in the future can ... also stay home to preserve the trails.

askvictor• 2 years ago

Do they not send the bill (for the recovery and track repair) to the person who got stuck?

olalonde2• 2 years ago

The trail in the picture clearly doesn't have gravel and doesn't seem like it's maintained at all. If it was a maintained gravel road, people wouldn't get stuck in the first place. It also doesn't seem like a life threatening kind of place. You can probably just have another car drag yours a few meters to get you unstuck.

3np2• 2 years ago

"I'll get it after the weekend"

Also, rentals.

jasomill• 2 years ago

The cited regulation[1] defines a "high clearance four-wheel-drive vehicle" as

A Jeep, sport utility vehicle (SUV), or truck type with at least 15-inch tire rims and at least eight inches of clearance from the lowest point of the frame, body, suspension, or differential to the ground. Four wheel drive vehicles have a driveshaft that can directly power each wheel at the same time and a transfer case that can shift between powering two wheel or four wheels in low or high gear. All wheel drive (AWD) vehicles do not meet this definition.

First, note that all recent Crosstrek models have 17" wheels and minimum ground clearance of 8.7" or more, so the only potential issue is "all wheel drive".

The last sentence is at best non-normative, so the actual requirements appear to be:

1. The ability to power all four wheels at once.

2. A drivetrain that includes a transfer case capable of switching between two- and four-wheel drive and, in four-wheel-drive mode, between two distinct gear ratios.

In particular, the regulation says nothing about differential locks.

Obviously the Crosstrek has (1), but not (2), so the citation is valid.

OTOH, (2) not only excludes Subaru-style all-wheel-drive systems and AFAIK all electric vehicles, but also several full-time four-wheel drive vehicles clearly designed for off-road use, including the Toyota Land Cruiser[2] and the military-issue AM General HMMVW[3], for no other reason than the lack of a two-wheel drive mode.

[1] https://www.nps.gov/cany/learn/management/compendium.htm

[2] https://www.landcruiserforum.com/manuals/2024-toyota-landcru...

[3] https://gear-report.com/wp-content/uploads/2017/03/Operators...

davidbanham6• 2 years ago

Definitions are hard. By that wording, any Land Cruiser outside the 70 series is forbidden because they're a full time 4WD. Nobody will argue that an 80, 100 or 200 series cruiser isn't a very capable 4WD.

I don't begrudge the parks people that wrote the regulation, though. Fundamentally what they're trying to say is just "Don't be dumb, only drive the trails in a vehicle that you know is capable, and if you don't have the experience to know that you have your answer".

The job of the regulation is to give them the ability to deliver an enforcement action where it's warranted. The job of the rangers is to use their judgement in a given situation, and either pull someone up or just wave hello. That's what's happened here, the system works.

nofunsir6• 2 years ago

I begrudge them. The law can simply say what you paraphrased and not try to get into nitty gritty, and leave it at good ol common sense. It's funny how when we interpret laws, they stop at what THEY consider common sense and not at the level that EVERYONE considers common sense. What I mean by that is, say you try to argue (for whatever reason) that your vehicle DOES meet the definition that was oh-so-difficult to write (Won't someone think of the law clerks?), they clearly have a conclusion already in their mind that they are so benevolently protecting us from, and YOU VIOLATED IT, YOU FIEND. But say you get up on the stand and try to argue the exact circumstances of your vehicle, you had a record of every bump and balance point, an IMS log, and a log PROVING the wheels never once slipped, even though you "DIDN'T HAVE 4WD". You could go as far as you want proving them wrong. In the end they'll just tell you to stop trying to be so pedantic and proclaim you guilty.

thrill• 2 years ago

4WD is poorly defined, and the NPS shouldn't be using it, especially by trying to classify an AWD system as something of lesser capability. The SAE even recommends using the term AWD along with 8 different subclasses, none of which use the term 4WD. Jalopnik can hand-wave all they want about what the NPS "means" but the definition should be from a recognized standard if legal action is going to be taken.

guax2• 2 years ago

I'm lost that people keep discussing the terms in terms of vague capabilities (not suitable for low speed muddy, etc) and not focusing on the actual mechanical difference. Is it the locking differentials or not? Is that the only distinction that matters in this case? I have no clue. Would a AWD not have it by definition? Do all 4wd have it?

Gibbon12• 2 years ago

Really you want five things if you're doing hard off road.

1. Locking differentials so all 4 tires spin in sync.

2. Extra low gears so you can crawl at a walking pace or less.

3. Clearance so you don't high side.

4. Strong suspension that won't get beat to death.

5. Tires that can take the abuse.

Typical AWD's don't have 1, 2 and 4. Lack of #1 means if one tire spins you lose traction. Lack of #2 in a manual transmission means you burn out your clutch. Lack of #4 means breakdowns and helping the guy that owns your auto shop put his kid through college.

You can lift AWD and put good tires on them.

Tip I've heard from people that live in places like rural Nevada having a 4WD gives you the opportunity to get stuck farther in.

blackeyeblitzar• 2 years ago

I’ve seen YouTube videos of stock Subarus handling tough trials in Moab and elsewhere. This type of distinction seems too simplistic and isn’t something that should result in threats to confiscate the vehicle or jail time.

nofunsir6• 2 years ago

Agreed. There needs to be serious statistics to back up the claim that it is SO COMMON the case where one wheel off the ground and thus you're stuck -- it's SO COMMON and the effects SO CATASTROPHIC that the punishment is potentially 6 months incarceration (aka ruining most people's lives permanently). I've seen plenty of 4wd vehicles stuck for myriad reasons. How about adding vehicle weight, tire pressure, tire diameter, tire width, tread depth, tread pattern, passenger count, mandatory shovels, mandatory boards, mandatory jacks, to the law??

And to think the rangers WENT OUT OF THEIR WAY to install secret trail cams and then pour over the footage or set up some CV software to auto send such damning letters to those who dare enjoy the national park!

This blows my mind. And these rangers should be ashamed of themselves.

hi_hi• 2 years ago

I was hoping to read the comments here to understand once and for all what the difference between AWD and 4WD is.

I'm still as confused as I was before reading the comments. It appears the answer is...it depends on the manufacturer/vehicle.

xnzakg• 2 years ago

From TFA:

The most consequential distinction between AWD systems and more capable 4WD systems is that most vehicles equipped with 4WD have one or more locking differentials that massively aid in off-road traction. While AWD systems are great for increasing driver confidence on slippery road surfaces and in light off-roading, they are easily flummoxed in more challenging off-road terrain, especially low-speed and low-traction situations.

carabiner2• 2 years ago

Numerous sources saying this is wrong. 4WD is not just AWD with locking diffs. Park service should call for cars that only have locking diffs if that's what they mean.

quicklime• 2 years ago

Pretty sure the Subaru Crosstrek mentioned in the article doesn't have one, but a WRX STI (also marketed as "AWD") has a lockable center diff.

I agree with the other comment: if the Parks Service wants locking diffs (or ride height or whatever else) they should say so, not rely on inconsistent marketing terms.

ip26• 2 years ago

4WD mechanically interlocks the front and rear wheels (setting aside the front and rear differentials). You cannot use 4WD on clean pavement because of this; the front and rear may need to turn at different rates which 4WD doesn’t allow. It’s ok off road because the wheels can slip a little in the dirt.

AWD generally does not mechanically 1:1 interlock anything, instead using things like torque converters. This allows it to be used on clean pavement. It isn’t as robust as 4WD, and has to respond to wheel slip instead of simply being 1:1 all the time.

doe_eyes2• 2 years ago

Yes, and even some of the responses to your comment are wrong (or rather, they are right only for certain brands). Which probably means that enforcement is going to be... hilarious.

What we can decipher is what the NPS is angling for. Many cars labeled "AWD" provide power to all four wheels, but if one of the wheels is not making contact with the ground, the remaining ones get little or no power. This is because the axles incorporate differentials - and if you have uneven traction, the torque delivered to the differential follows the path of least resistance. The end result is that it's deceptively easy to get stuck on uneven terrain, in mud, or in snow.

But then, some "AWD" cars actually provide good workarounds. In the simplest variant, the car automatically applies brakes to the free-spinning wheel, forcing the differential to power the other wheel. Less wasteful and more responsive solutions that mechanically sense torque imbalance also exist.

And then, some "4WD" cars work roughly the same way! For example, some models of RAM 3500 are labeled as four-wheel drive (4x4), but rely on torque-sensing ("Torsen") limited-slip differentials. Other 4x4 cars might have a button to physically lock the differentials. This is widely regarded as the best option, except it's dangerous on paved roads (and makes turning hard).

thefroh• 2 years ago

they're ambiguous terms, and the ruling will be "I'll know it if I see it!"

it's more useful to consider what people suggest for a track.

- "you're going to need a diff lock"

- "you're going to need high clearance"

xattt2• 2 years ago

“What do you mean that I can’t get on this trail in my AWD Nissan Maxima?”

Daneel_2• 2 years ago

Engineering Explained on Youtube has a very comprehensive video covering this:

https://www.youtube.com/watch?v=Jk246sutET0

At a very simple level it boils down to: Do you have a transfer case? If yes, then it's a 4WD.

karolist• 2 years ago

A transfer case is something BMW calls the thing that attaches to the side of your transmission to provide power to front wheel shafts, this does not mean the car is 4WD. Yes, still confusing.

https://awd.tech/de/apps/catalog/transmission/atc300-bmw

blitzar• 2 years ago

it depends on the manufacturer/vehicle

& the marketting department.

Beretta_Vexee2• 2 years ago

The cars are equipped with a differential that distributes power differently between the wheels. This is particularly useful for preventing the wheels from squealing when cornering. In a bend, the four wheels do not turn at the same speed between the inside and outside of the bend. This gives you better grip, a smoother ride, etc. It's really essential.

- When you have two wheel drive you only have one differential between the two wheels. - When you have four-wheel drive you have three differentials, one between the front wheels, one between the rear wheels and one between the front and rear. So far so simple.

Now one of the problems with differentials is that if one of the wheels loses traction, it gets all the power back and spins in a vacuum.

Finding yourself with a wheel in the sand, in the air, on the snow, etc. is very common when driving off-road or in the mountains. This problem has been solved with the differential lock, which can be manual or automatic. When locked, the differential is locked and power is transmitted equally to the wheels. So you can get out of your sandy or snowy hole. That's what we call a 4x4.

A All-wheel-drive has no differential locking system.So if one wheel loses its grip, the vehicle is stuck. There's nothing you can do - all the power will go to the wheel with the least grip.

So AWD is particularly unsuitable for off-road use and shouldn't be sold as such.

Some off-road vehicles do not have a differential, such as quad bikes or buggies. Perfect for mud, not so great on the road.

https://en.wikipedia.org/wiki/Differential_(mechanical_devic... https://en.wikipedia.org/wiki/Locking_differential

criddell• 2 years ago

There are exceptions. I believe the Kia Telluride SUV is sold as AWD and it has a locking differential system (or at least it’s an option). There are probably others as well.

aeonik7• 2 years ago

This is not true for a lot of all wheel drive systems these days.

Subaru for example has had adaptive AWD since early 2000s.

https://youtu.be/YIY392Qtu0I?si=WCvlM1LCGezDcJVF

itsoktocry3• 2 years ago

I'm still as confused as I was before reading the comments.

I agree, and I know a bit about this!

The reality is very few vehicles on the market are legit "off-road" capable. But, the other side of that is not every trail is legit "off-road", either. Just because there's no pavement, doesn't mean it's "off-road".

There's an entire spectrum of vehicles and trails where normal people can get off the beaten path.

smitelli• 2 years ago

Up until not long ago, you could get away with this test: "Do I, as the driver, have to stop, think, and make some choice to command the car to change some setting that governs whether or not I get across this patch of terrain?" The 'stop' step is important; certain classical 4WD shifts require the vehicle to be stationary. The automatic-ness of the AWD systems -- no pesky second shifter -- was the differentiator.

Now that we have knobs for different "driving modes," the the ability to slam it into whatever position whenever we want while an ECU figures out how to keep a gearbox from exploding, it's genuinely hard. Still, the presentation of a setting like "lock/unlock" and "two/four" and "high/low" is the standard I still go by (right or wrong).

alvah• 2 years ago

Good luck making a citation stick if the vehicle has four wheels and they're all driven, i.e. 4WD

toofy• 2 years ago

This thread is a perfect example of why we need to reign in marketing and its insistence on misleading people.

Because and only because i’ve been lingering in the off-roading community for a few years i personally understand why the NPS end goals are not only reasonable but probably necessary. but i feel terrible for the sheer number of people who have been intentionally duped by marketers.

i’ve seen it repeatedly, someone buys an “all wheel drive” truck or suv, and from the initial first commercial they see all the way through to the salestrash, they were misled.

over and over they end up justifiably frustrated finding out they’ve spent tens of thousands of dollars being misled on their vehicle’s capabilities only to learn their “off-road AWD” vehicle really really shouldn’t leave the suburban pavement. and that the misleading was all a ploy by marketers and their insistence on muddying the waters.

this is far from limited to auto manufacturers, we see this misleading trash across the entire board.

we desperately need to get back closer towards something resembling honesty in marketing.

doe_eyes2• 2 years ago

But is the lingo really misleading? There's nothing incorrect about "all-wheel drive", "four-wheel drive", or "4x4". The engine is turning all four wheels.

The behavior of open differentials is somewhat counterintuitive, but that applies to 2WD cars too. People get one wheel buried or up in the air and can't comprehend why the car is not moving. Is that a failure of marketing or consumer education? Probably the latter.

For what it's worth, I've seen quite a few "real" 4WD cars with locking differentials getting stuck in silly ways, often because the driver simply had no idea how to lock the diff, or didn't turn off traction control, or just kept flooring it and making the situation worse.

To me, the only potential dishonesty isn't the naming, it's the imagery of SUVs traversing rugged terrains. But that's not strictly a lie, more of a missing footnote: "don't try anything more rugged than that".

giantg22• 2 years ago

"often because the driver simply had no idea how to lock the diff,"

Most of the locking diffs out there are automatic, like the G80. They're basically a locking limited slip diff. It uses slip between the wheels to throw a cog (for lack of a better term) that locks the diff. It then unlocks (drops the cog) after the torque is unapproved. This is very different to use from the older way of locking diffs via the hubs or the high end electronic switches that enthusiasts use.

arghwhat6• 2 years ago

The first step is to stop pretending AWD and 4WD can sensibly mean different things… unless your number of wheels differ from 4. The naming is truly idiotic.

Instead, be clear about any locking or torque split requirements, so you don’t take your sports SUV with no locking diffs and a 70/30 Torsen center differential on the trail. E.g., “this is an advanced trail that requires three locking differentials or equivalent”, and for lighter trails “this trail requires at least limited slip differentials”.

dotancohen4• 2 years ago

How about the AWD Teslas? They have independent front and rear motors, but I don't know if the rear and/or front diffs limit slip. Even if they don't, the ABS could hold a caliper to prevent wheelslip (Some Mercedes 4WD or AWD had an open differential and used independent brake control to limit slip, it was excellent for mud and sand, I don't know about other conditions).

jokoon• 2 years ago

Capitalism doesn't really reward honesty.

That's why it matters to properly regulate the market.

spacebanana73• 2 years ago

That's over simplifying.

Sketching out the game theory, in markets with repeated interactions there's a great reward to honesty. A local baker wouldn't do well by giving customers food poisoning by slacking on hygiene. Even absent regulation customers would stop visiting for daily lunches after a while.

However in single trade markets, there's a great temptation to be dishonest. A big city realtor selling to overseas buyers has a potentially incredible reward for being dishonest about the value of a property. And absent regulation (and enforcement) it can be very lucrative to be a liar.

tomohawk• 2 years ago

Lying about everything is a hallmark of societies under the thumb of autocrats or socialists. It's a survival skill.

FredPret6• 2 years ago

This notion of regulation is just the desire to offload your duties as a responsible and intelligent market participant to a third party.

It’s intellectually lazy, and it should be blindingly obvious that, in a universe with more than one mind in it, the principle of caveat emptor will always be needed regardless of economic system. In fact, you need caveat emptor for daily life, not just economic decisions.

Here’s why: who does the regulating?

The government?

Neither politics nor the civil service rewards honesty. These occupations have feedback loops that stem from popularity with the public or with one’s union and are thus not reality-based.

In fact capitalism comes closest to rewarding honesty in that consumers go on forums such as this one and then make informed choices.

For example, I once bought an AWD car knowing full well it’s not 4WD. It’s still 100x better than 2WD on snow and gravel. I liked my AWD car - money well spent.

ssss11• 2 years ago

Thank you. So well articulated. This trash you speak of is absolutely everywhere. There’s no honesty in marketing any more.

switch007• 2 years ago

When was there honesty in marketing?

Isn't looking for honesty in marketing like looking for a nutritious meal in a spoon of sugar?

remedan• 2 years ago

Are you implying there used to be honesty in marketing?

itsoktocry3• 2 years ago

vehicle really really shouldn’t leave the suburban pavement

This is also nonsense.

I'm an avid fisherman and (former) hunter. I grew up in Northern Ontario.

I had an Subaru Forrester and took it everywhere. Yes, there's a big difference between AWD and 4WD. Yes, you can get in trouble without a locking diff. Yes, ground clearance will be an issue.

But the idea that these vehicles can't leave the pavement is simply not true. They are surprisingly capable. And as someone who now owns a half ton pickup for the same usage, their small stature on the trail is an advantage.

we see this misleading trash across the entire board.

Where are all of these misleading ads? Maybe I'm out of the loop, but where are these cars being advertised as "off-road"?

deelowe2• 2 years ago

Subarus are probably the most capable awd vehicles. Imagine a cr-v or even worse the bronco “sport” which is pretty terrible compare to the non-“sport” version.

ghaff3• 2 years ago

There's certainly a big gap between suburban pavement and serious rock-hoppng that many vehicles and drivers can navigate up to some point even without AWD. Certainly many reasonably-maintained gravel roads are not an issue.

That said, SUV and truck manufacturers do tend to picture their vehicles in wilderness settings and the like so there is a certain go anywhere/do anything implication even if it's not explicitly stated.

TheCondor• 2 years ago

There sure are a lot of actual 4WD trucks without lockers when they are sold. I have to wonder what the difference is between a Tacoma sport and an AWD vehicle, I think it’s 2WD mode and maybe clearance. I think there are even jeep gladiators without lockers… is that a jeep or like a cool looking suburban pavement car?

“Off-roading” is a big thing that means different things. I live in Colorado, in the front range area (Boulder) and the popular guides sort of divide trails in to three: green easy, blue moderate and red hard. Most of the blue trails you can do in a bone stock 4WD road truck, probably most AWDs with clearance. You’d want to take it easy and think through a couple sections but it’s doable. We’ve gone to multiple 10th mountain division huts in Subarus, made it with no scraping or problems. This is most trails. Now there are the reds and the hard reds, you basically need a modified vehicle for them. There are some “trail ready” trucks coming from the factory now, I’m under the impression that the “off-roading community” usually feels that even those need modification. Modifying the vehicle and the technical trail challenge is the idea for them.

The difference is driving on technical obstacles for that specific challenge, the driving and the building of the vehicle versus driving on rougher terrain to get to a location. NPS probably also frowns on rock stacking and other “recovery” techniques when a vehicle cannot clear an object.

dakna• 2 years ago

I have to wonder what the difference is between a Tacoma sport and an AWD vehicle, I think it’s 2WD mode and maybe clearance

As a long-time AWD driver who entertains the idea of getting an offroad vehicle at one point, this is my current understanding:

AWD: If one wheel slips and starts spinning, all other wheels stop turning. You are stuck. Clever electronics applying the brakes on the spinning wheel can help to redistribute the torque to other wheels, you might get unstuck.

4WD: If one wheel starts spinning, only the other wheel on the same axle stops turning. The transfer case is locked, and the other axle still receives torque. If both axles have one spinning wheel, you are stuck.

4WD with one locker: If one wheel on the axle with a locker starts spinning, the other wheel on the same axle still receives torque. If both axles each have one spinning wheel, you can still move the vehicle with one wheel still receiving torque.

4WD with locker on both axles: If you manage to get stuck with all 4 wheels spinning you should reflect on how the heck you ended up in that situation.

l1tany11• 2 years ago

As someone who has spent a lot of time building and racing cars… yeah the marketing is nuts.

A few years ago Porsche came out with the Taycan. One of their big marketing pushes was that it was better on track than a Tesla model S, because on paper it was worse in many ways (more expensive, less range, less power, worse charging network, etc). The sad thing was all the magazines and journalists seemed to be happy to parrot this position. Porsche bragged about their ring time. Internet commentators agreed. The Taycan Turbo S was a track weapon!

The reality? The car is heavy, it’ll eat tires. I’ve seen guys in cars like that (noobs mind you) cord a set of tires in 1 session. Tracks eat fuel like crazy, I normally brought 4-5 5gallon fuel cans, and a full tank. I could do half a tank in like 8 laps. Electric? What track has super chargers?

And the ring time? $200k+ Taycan turbo s matched the $38k civic type R.

But marketing. And the journalists who really do know better were happy to play the game. Every car seems to be marketed on track now. For most cars, even seemingly performance oriented cars, tracking the car voids the warranty.

Really the brands know that they are selling a fantasy, and very few people will actually even try that stuff. They just want the aura of it. Especially Americans want to buy 120% of the car they need. Need to take a freeway on ramp? Good thing this car has a ring time of X! Should be no problem! Thinking about getting a boat? Better buy an F-250, just to be safe!

OptionOfT• 2 years ago

In general we should put a stop on marketing claims unless they are proven.

Walk into a store and read the ridiculous claims left and right. Why is it allowed to print something on a label that you can just make up? Water is sold as if it has some kind of magical properties. It's just water.

It disgusts me.

And when you buy a car you literally sign a piece of paper stating that you cannot derive any value off the claims that the sales person made to you.

nofunsir6• 2 years ago

PSA: Regarding the National Park system, it is now gate-kept by Booz Allen Hamilton (of McLean, VA, spooky). Yes that Booz Allen Hamilton. They made millions creating a database that keeps track of where everyone recreates[1] and make more millions auctioning off access to the parks.

You thought your lottery fee on that permit you didn't get at least went to a good cause? lol. Nope. It went to Snowden's old employer.

It's also convenient that the park system (and others) are conveniently NOT ACCEPTING CASH whenever it's inconvenient for them to do so.

It further creeps me out that the OP never saw a single soul yet got a CCP-esque letter. This means they've also installed secret cameras, and that the Recreation.gov database perhaps has some extra tables to attach "incidents" such as this.

nofunsir6• 2 years ago

[1] https://www.youtube.com/results?search_query=booz+allen+hami...

bagels• 2 years ago

If you are a Subaru owner, just buy a chrome 4x4 badge on eBay.

boesboes• 2 years ago

The marketing department strikes again!

When I was younger we made a joke about how there was 'the commission' that made everything suck more. Just to fuck with us. For instance making sure hot dogs come per 8, but buns per 6. Or the '3 person portion' with 4 equal size pieces. Or making the plastic on top of packaging so thin the 'open here' tabs will never work.

Anyway, I've since learned this is actually called 'marketing departments' and that commission that makes everything suck is just emergent behavior. Probably anyway ;)

iramiller• 2 years ago

The biggest missing piece in these definitions? The tires. Most cars these days come with a very highway biased tire. These tires will fail very quickly in most conditions found on off road trails, especially those that are designated as 4x4 required. Failure can be as innocuous as limited traction or complete such as a flat tire from a puncture. If you are in a situation where a tire is punctured from lack of durability how do you think that space saver spare (or can of fix-a-flat) is going to help you get out?

The second major issue with AWD systems is often the clutch based systems that are engaged to transfer power ‘from the wheels that slip to the wheels that grip’. When used in demanding conditions these systems can overheat and shutdown. This also applies to brake biasing systems as well (brakes applied to spinning wheels to transfer torque to other wheels). It can be especially challenging for brakes as there is generally not sufficient air flow over the brakes to cool them during slower speed off-road travel.

jumploops• 2 years ago

As someone who recently purchased a 4x4 vehicle after getting stuck in an “all-wheel drive” vehicle…

I can’t fault the NPS for these actions.

Every manufacturer seems to have a different definition of 4WD, with the line between AWD getting blurrier and blurrier.

Sure, some AWD systems are pretty capable with automatic electronic braking to drive power to different wheels (mine wasn’t).

Even my new 4x4 vehicle also has this (A-trac) and I rarely need to lock my diffs, it’s great!

But when push comes to shove, road conditions are unpredictable and having a high-clearance vehicle that you can manually override which wheels are getting power is a lifesaver (literally).

mberning• 2 years ago

People that think the government is correct here need to watch the video of a Subaru Forster casually summiting a huge sand dune while many “proper off road vehicles” fail to do so.

1970-01-01• 2 years ago

Completely omitted are tri and quad motor EVs, which meet both definitions of 4WD and AWD (inclusive OR).

foobarbecue5• 2 years ago

So I have a 2015 Mitsubishi Outlander Sport, which says it has 4WD (not AWD) but from what I can tell the technology is equivalent to what Subaru et al calls AWD.

Am I right about that?

National Park Service Will Cite AWD Drivers for Driving on 4WD-Only Trails

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