Is AWD oversold?

[giant_mtb]

Huh, I hadn't realized that they switched to FWD/AWD instead of RWD/4x4.

Indeed.  I believe theirs is a 2010? 2011?  Whatever year was first for the new model. They're selling it now that dad has Frontier and mom has Q5.  That Q5 is gonna be BEAST with snows.

[Submariner]

Meh.  It's only oversold if you hold it up to be more than it's worth.

My dad had an S430 4Matic which, even on all-seasons, managed to handle un-plowed roads (about as high as you could raise the air suspension) or slick highways with confidence. 

However, there have been plenty of cases where my moms Range Rover, with snow tires (and occasionally, chains) was the only way a road could be traversed.  There have been a few times where you absolutely need ground clearance and locking difs, though I suspect they are very few and far between.

The last time I drove on bad roads, my town got 2.5 feet of snow the night before.  There was between 12 and 18 inches still on the roads, and aside from my dad in his equally equipped G500, there were perhaps 8 or 10 other non-town vehicles we encountered the entire day.  All were SUV's or trucks, all had lockers, t-cases, lifts (or adjustable suspensions) and snow tires/chains.  A stock Outback wouldn't have made it down the driveway, let alone anywhere around town. 

[Raza]

I was an AWD non-believer until I drove my brother's S4 in a snowstorm.  Holy shit...even on all seasons, it acted like the snow wasn't even there. 

[AutobahnSHO]

I was an AWD non-believer until I drove my brother's S4 in a snowstorm.  Holy shit...even on all seasons, it acted like the snow wasn't even there. 

welcome to reality.

[Laconian]

We took the Subie up Mt. Rainier in a restricted stretch of road that required all 2WD cars to chain up. No problems at all. What was fun was hearing the CVT and ABS really going to town to keep things pointed forward and pointed in the right direction. The resulting ride was drama-free, but managing the traction made the car feel like it was possessed by demons.

[AutobahnSHO]

We took the Subie up Mt. Rainier in a restricted stretch of road that required all 2WD cars to chain up. No problems at all. What was fun was hearing the CVT and ABS really going to town to keep things pointed forward and pointed in the right direction. The resulting ride was drama-free, but managing the traction made the car feel like it was possessed by demons.

[Eye of the Tiger]

We took the Subie up Mt. Rainier in a restricted stretch of road that required all 2WD cars to chain up. No problems at all. What was fun was hearing the CVT and ABS really going to town to keep things pointed forward and pointed in the right direction. The resulting ride was drama-free, but managing the traction made the car feel like it was possessed by demons.

You could probably pull the ABS system fuse and have ot behave a bit better next time.

[Laconian]

Nah, I think it was doing its jerb.

[Eye of the Tiger]

pull all fuses. drive enthusiast.

[SVT666]

Any such videos are carefully crafted IMO to play to a particular car's strengths or weaknesses.

There are many iterations of AWD and particular power split - how, when, magnitude, response.

The first video shows the G37x (AWD) not moving with the rear wheels on rollers. I can confirm however the G37x's snow and wet road traction/performance is excellent (and I drive a lot in both).

I agree. The G's AWD rocks in the snow.

[SVT666]

People who are serious about snow traction switch to the tires appropriate for the job. Once that's done drive wheels are largely irrelevant.....

LOL

[SVT666]

A true 4wd with locked diff and bald tires will be better in snow than rwd and best snow tires available.

LOL

[Laconian]

LOL

Yeah, my friend tested that theory a few years back. Car went sideways into the ditch. Driving was scary, it was like a form of surfing.

[Eye of the Tiger]

Yeah, my friend tested that theory a few years back. Car went sideways into the ditch. Driving was scary, it was like a form of surfing.

Like surfing, it's fun and safe if you know what you're doing.

[Raza]

welcome to reality.

I can't wait until I have money again and I can buy that Evo I want. I'll never worry about snow again. Sunny and over 40? Z4. Anything else, Evo. Perfect two car garage for someone who doesn't have to haul things.

[BimmerM3]

Like surfing, it's fun and safe if you know what you're doing.

I don't know what I'm doing. This is why I bought 4x4 and snow tires.

[Eye of the Tiger]

I don't know what I'm doing. This is why I bought 4x4 and snow tires.

I like surfing. That's why I bought an Element, brah.

[giant_mtb]

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

[giant_mtb]

LOL

I LOL at the shit people here say about Winter driving constantly.  But they always think they're right. It's bizarre.

[GoCougs]

Drive wheels make a huge difference. Number of drive wheels makes a huge difference. Type of tire makes a huge difference.

[giant_mtb]

Drive wheels make a huge difference. Number of drive wheels makes a huge difference. Type of tire makes a huge difference.

Try telling Sporty that. He lives in a Carolina. He knows a lot about Winter driving.

[SVT666]

Tires make a bigger difference than drive wheels. Tires are the only thing connecting you to the road.

[BimmerM3]

Tires make a bigger difference than drive wheels. Tires are the only thing connecting you to the road.

Yeah, 4WD doesn't do shit when you're sliding down a hill.

[AutobahnSHO]

Tires make a bigger difference than drive wheels. Tires are the only thing connecting you to the road.

meh, when I was a kid they didn't salt the roads. Whitepacked roads from Nov-April plus snow storms, slush, ice, etc...
I drove places on bald tires you wouldn't believe.    Real 4wd with the right gearing FTW.

[MX793]

4WD can help you get going (2x-4x the forward traction of a 2WD with comparable tires, depending on differential type), but does little to help you turn or stop.

[AutobahnSHO]

4WD can help you get going (2x-4x the forward traction of a 2WD with comparable tires, depending on differential type), but does little to help you turn or stop.

Those suck in the snow anyway.

[BimmerM3]

Those suck in the snow anyway.

I have no idea what point you're trying to make here.

[MX793]

Those suck in the snow anyway.

Traction all around is diminished in snow.  How much will depend on tires (tread depth, pattern, and compound).  2WD will have ~2x-4x the stopping traction than it has driving traction, depending on weight distribution over the drive wheels and differential type (e.g. can be a little less than 2x with a FWD and Limited slip).  4WD will have 1x-2x the stopping traction relative to driving traction, differential dependent.  The difference between a modern snow and modern A/S tire, both with fresh tread, is ~20-25% on snowy surfaces.

Let's say we have two vehicles of the same weight.  One is FWD with a limited slip and the other is a AWD/4WD with an open front and limited slip rear diff.  The stopping traction to driving traction ratio on the FWD is 1.9.  The same for the AWD is 1.67.  On all-season tires, both stop in 150 ft from 30 mph on uniform snowpack.  The FWD takes 285 ft to accelerate to 30 mph, the AWD takes 250.5 ft.  Now put snows on the FWD.  Traction is improved by 20%.  It now takes 228 ft to accelerate to 30 mph, which is better than the AWD.  It also stops well shorter, at 120 ft.  And that's all assuming both vehicles are running fresh tires.  Throw bald A/S tires on the AWD, and the AWD looks even worse.

Now, since limited slips on FWDs are relatively rare, let's take the example of an open diff FWD.  Many AWD are open diff front and rear, but we'll give it the benefit of one limited slip.  Same parameters as before, except the stopping to driving ratio on the FWD is now 3.8.
40-0:
FWD, A/S tires = 150 ft
AWD, A/S tires = 150 ft
0-40:
FWD, A/S tires = 570 ft
AWD, A/S tires = 250.5 ft

Now, replace the A/S tires on the FWD with snows, and replace the tires on the AWD with bald versions of the same tire.  Let's, generously, give the bald tires 50% of the traction that fresh ones would have.

40-0:
FWD, snow tires:  120 ft
AWD, bald A/S:  300 ft

0-40:
FWD, snow tires:  456 ft
AWD, bald tires:  501 ft

The only thing this doesn't account for is that snowy road surfaces seldom have uniform traction, and the AWD with one limited slip (or two, or one or more lockers) has a much higher probability of having a wheel sitting on a higher traction patch of road surface than a 2WD w/ open diff.

[AutobahnSHO]

I have no idea what point you're trying to make here.

You have to drive more carefully anyway.

BTW if you drive automatic and you are coming up on a stop where antilock kicks in or you're sliding, putting it into Neutral helps so the front tires aren't still getting pushed by the engine....

[AutobahnSHO]

Traction all around is diminished in snow.  blah blah

what about full locked-diff 4wd??