As one Subaru Crosstrek owner recently learned the hard way, it bears repeating that all-wheel drive is not the same as four-wheel drive. A Subie owner posted a warning letter they received a month after driving on Colorado River Overlook Road in Canyonlands National Park to the r/NationalPark subreddit. The letter notes that this particular road is restricted to 4WD vehicles only, and the Crosstrek is equipped with AWD, not 4WD. It also warns that they may face serious consequences if they’re caught taking an AWD car on a 4WD-only trail again.
I didn’t know the difference so I looked it up: https://www.spinny.com/blog/index.php/awd-vs-4wd-the-difference-explained/
AWD has the ability to drive all four wheels, but not necessarily all of them at the same time. 4WD has the ability to drive all four at the same time.
The main difference is the additional physical gearing for 4 high and 4 low gears, both of which have different gearing than “regular” drive.
I have an older Audi with a Torsen Quattro AWD system, and an ancient Toyota 4Runner with 4WD. The 4Runner can be switched into either 4 wheel high or 4 wheel low gears to deal with different conditions. The Audi always has the same gearing, it cannot be switched.
It’s like the gears on a bicycle - 4 low is the one where you barely move while standing on the pedals - maximum torque per revolution.
You can go rock crawling in a 4Runner in 4 low. You really should not go rock crawling in an Audi or Subaru without 4 low, no matter how much ground clearance the vehicle has.
The National Park Service has this rule because it doesn’t want to spent time and taxpayer money rescuing people who think AWD is the same as 4WD with a low range gearbox.
Subaru has x-mode for difficult terrain, which is different gearing. They also have hill descent. https://www.sportsubaru.com/subaru-x-mode.htm
Why would you want 4wd with wasted energy when you could have symmetrical awd and get all the power to wheels that have traction, skipping those that don’t have traction?
I only see awd outperform 4wd when it comes to a subie, but other awd systems from other manufacturers are probably not up to snuff.
Edit: meant to say symmetrical awd instead of slip differential.
