4WD vs AWD

The bulk of Subaru’s sold are the Subaru Outback. Its ground clearance is around 8.5-9" dependant on model/tires. It bests or meets quite a few SUV’s. If Audi owners want SUV clearance they opt for the 8"+ Audi All Road.

That ground clearance is measured at for the differential ONLY. Not the rest of the body. The only time I ever hung up a differential was plowing through deep hard packed snow. It’s much easier to get stuck if the snow is lifting the body in the air…SUV’s usually have a lot more clearance there.

I will also only add there are many SUV’s with AWD that are real off roading vehicles like Jeep, Toyota/Lexus Land Cruiser, Land Rover. They do have a locker for the AWD if needed but most do incredibly well off road without any intervention.

I haven’t seen any comments about the GM approach, 2wd, auto, 4hi and 4lo, The auto kicks in 4wd when needed, It is my first 4wd vehicle but found the auto a nice feature in winter, but really got 4wd for getting the boat in and out of some crummy launches. The other decades of driving have been rear 2wd pickup trucks and cars. Sure I had some trouble sometimes but never needed a tow out.

I own a Trailblazer with the auto 4 mode. I’ve used it many times in questionable conditions and while you can definitely feel when it kicks in, it’s always done so in a smooth enough transition of power so it doesn’t cause any handling issues. Really a nice feature for those times when the snow and ice are really intermittant and you have to ride on dry pavement most of the time. No need to keep switching in/out of 4 HI.

Which Toyota is AWD??? The only Jeep I know of that’s AWD is the Grand Cherokee…and I don’t consider a Unibody vehicle a TRUE off road vehicle. But I will agree they do fine in snow. As I said…AWD is GREAT for over 99% of the any road conditions you’ll ever see. And I’d personally would probably buy a AWD vehicle if it met my criteria for off-roading and towing. I’ve yet to find one that does.

I haven’t seen any comments about the GM approach

For the record it’s actually is Chryco’s approach. Chryco’s New Process Gear (now called Magnum) designed this system and sells to GM. Actually GM owns 49% of Magnum and 51% owned by Chryco. 35+ years ago when I worked there on a summer job is was 100% owned by Chryco.

Toyota Land Cruiser and Lexus LX470 are both AWD and can lock differential to become 4wd if need be.

I drive a 2004 Mazda Tribute (i.e. Ford Escape). It is an AWD system that is in front wheel drive mode almost all of the time. From what I know, the ABS system monitors the speed at all wheels and is constantly comparing the speed of the front wheels vs. the speed of the other wheels. If it finds, for example, that one of the front wheels is turning 20 mph while one of the rear wheels is turning at 3 mph, that discrepancy is enough to tell the computer to send power to the rear wheels via a differential. There is a slight delay between the rear wheels kicking in and the front tires slipping. This is where AWD has a weakness…you can be stuck at low speeds, spinning the front wheels for a couple of seconds before the rears engage and by then its too late.

Luckily, my 2004 has a ‘LOCK’ button on the dash. When depressed, the lock feature overrides the AWD sensors and computer, and sends 50% power to the front, 50% to the rear. This is equivalent to putting a traditional 4WD into 4 HI. In 2005, Ford, Mazda and then Mercury (after introducing the Mariner) dropped the lock button leaving the Escape/Tribute/Mariner to a pure AWD system. This is the main reason I opted for a 2004.

Also not mentioned: braking. In a traditional 4WD setup, you have an engine braking advantage by using the low gears (either in 4 HI or 4 LO) when descending a slippery hill. With both sets of wheels mechanically connected to the engine, you can crawl down a hill with better control in 4WD. This is not an option in an AWD as the AWD system will not be engaged unless the wheels are spinning…not sliding. Someone please correct me if I am wrong. This is another advantage of the lock feature on my Mazda. Again, by locking the AWD system into a 50/50 power split, I am replicating a 4 HI setup and can engine brake all four wheels (or at least one of the two, front and back).

I tow a covered snowmobile trailer with my AWD Mazda, and I have never been stuck (to date) after many excursions down snow covered, hilly roads in the Adirondacks, including backing up hills with an icy surface…not to mention, snow-filled parking lots with 12" of the white stuff. I usually use the lock feature before entering these precarious situations. However, it should be noted that when I am using AWD only, the Mazda rarely comes out of front wheel drive only (the driver can feel the AWD system engage) even in snowy situations as described above. FWD alone will get you in and out of 95% of driving situations. However, the AWD does come in handy…and, the bottom line is that I highly recommend to the original poster that if he/she gets an AWD, find one that has a lock feature!

Excellent post. I noticed what you speak of at ski resorts and in a tough driveway at a family house. Honda AWD is absolute garbage like you speak in tough conditions. I noticed Toyota Highlander is similar too. Current RAV4 fortunately has the locker.

The only full time AWD as posted earlier is Subaru/Audi/VW and guarantees front/back both turn.

AWD does not mean the same thing across makes.

Thanks for the kind words. I didn’t realize that Honda was without a locking feature for the AWD system. Kind of disappointing considering the price tag. As mentioned, the reason I didn’t buy a 2005+ Tribute/Escape/Mariner is because they got rid of the lock feature, making the AWD system just like the Hondas. Considering the places I find myself off-road and in the winter, I need a true 4WD at times. Totally unrelated, but the 2004 Tribute also has the spare time stored inside, in a well under the cargo area floor. 2005+ models have the spare mounted underneath with a cable drop set-up. I live in an area that gets 200"+ of snow each year, meaning lots of road salt exposure. Those cable drop systems corrode, rust and cannot be used after just a few years…even with a maintenance.

The Honda CVR is very environmental friendly and when equipped with good winter tires (tirerack.com) will go just about anywhere.