AWD vs. 4WD

[Scoot]

Can somebody explain the difference between all wheel drive and 4 wheel drive in language that a total mechanical (Contact Us Please) (i.e., me) can understand? I've asked this question to a half dozen people and gotten a half dozen different answers that don't make much sense to me.

[Scoot]

Quote:

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Yeee haaaaa. Got it now Scoot?! Lovin it....just lovin it.

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Yup, definitely clear as mud now! Oh well, I don't feel so dumb for asking the question anymore...

[Ufatz]

Seriously Scoot, all the boys are pretty much spot-on in their assesments of AWD v. 4-WD. In the "old days" up in the far frozen north, we used to love to watch the cheechakos with their new 4X4's after the first snow. And all winter for that matter; they assumed that with their new "four wheel drive truck" they could drive like nuts and nver get stuck. Usually, the FIRST thing they did, was drive right OFF the road!! Down here in flat-lander country, the boobs slam 'er into "four by four" and haul assets down I 94, with little understanding of just how unstable their vehicle now is.

But then.....what do I know! HA!

Enjoy life boys....its way shorter than you think.

[cold one sd]

It is always interesting to watch a guy with his first 4WD when he finds out that his tank won't go through anything that he thinks it will and you can actually get stuck in a snow drift and have all four wheels six inches off of the hard surface.

[BobT]

You bring up a good point to remember, Ufatz.

A common misconception is that it is better to drive on ice with the 4WD engaged but this is quite untrue, especially at speeds over 30mph! I found this out the hard way.

When a rear wheel drive vehicle goes into a spin we all know the correct action is to throttle back and steer out of it. When front wheel drives first hit the market it was difficult for us to remember NOT to throttle back when in a tail spin but rather throttle up slightly and DRIVE out of it. However, in 4WD neither of these options are applicable because no matter which option you choose you are applying the same force to all wheels and so you can't drive or steer out of a spin. Could almost just as well let go of the steering wheel.

I got myself into this at 50mph once and when I was sideways I could see the grill of an 18-wheeler in my passenger window. Fortunately, and I don't know how, I had the where-with-all to reach down an throw my transfer case into 2WD and then was finally able to steer out of my predicament and avoid a serious situation, not to say it wasn't already.

Ever notice that half of the vehicles in the ditch after the first snow are 4WDs? Use it to get going but then take it out of 4WD for driving. You are also less likely to forget how slippery it really is too.

Bob

[Fishbreath1]

I have a 4wd system in my 4runner that has a center diff. and isn't awd, or isn't called that, anyway. It lacks the viscous coupling. Rather, it uses a torsen center diff. to allow up to 49% of the power to go to the front wheels, while normally it is 30%. Torsens are used as rear diffs. as well, just another form of an open differential. Also, the torsen locks up, giving "true 4wd" performance. Meaning you can't or shouldn't go around turns on dry pavement. I'm confused also, but I don't care cuz I haven't got stuck in my runner yet. Like Joe Dirt's dad says, "How does the posi rear end in a Plymouth work? It just does..."

[upnorth]

Dude you hit the nail on the head. I have been driving 4X4s since 1980 and the one thing I can tell you is they will get you going on slippery stuff, but they don't help you turn or stop. You can usually climb an icy hill that you can't stop coming down. It can be harder to turn on ice locked in than locked out, the vehicle wants to go straight.

Learnt all that stuff the hard way And a few times it was rather scary

[chickeywing]

Look what you started! The common thread is: 4WD runs in 2WD mode UNTIL you tell it to turn all wheels while AWD can spin any wheel at any time, as needed. I knew a guy that drove through snow in 2WD until he got stuck. That's when he shifted into 4WD and backed out. He NEVER had to dig his truck out. 'AWD is for Yuppies and 4WD is for people that can drive???' Let's chat about anti-lock brakes while we're at it.