AWD/Full-Time/Centre-Diff vs Part-Time 4WD in greasy snow?

[calicamper]

I currently drive an 80.

I'm wondering if there is any real performance difference at highway speed, in snow or on icy patches, between a vehicle with a centre diff (like my 80 or my previous Impreza or a 4Runner) and a vehicle with part-time 4WD (like most American pickups and the Tacoma). Basically, I'm looking to remove that factor from my personal vehicle choice grid, if it is unimportant.

Thanks,

A.

Good question and one that I discussed a few years ago with a good friend and total gear head nut case. He had a very interesting point which I had not considered. He said the older full time AWD machines like the 80 had to be engineered with a system that was balanced as best as possible from a mechanical stand point to make it good in slick pavement conditions which case the 80 AWD system is very balanced and noted for being pretty good on the slick pavement type conditions. This is also why Subaru AWD system is very good given by design its very balanced left vs right and how the power gets put to the corners.

Newer vehicles due to the fancy capability of ABS systems and stability systems paired with fancy traction logic systems as he pointed out can get away with being not as well engineered regarding being balanced meaning if the left side has a tendency to break loose before the right side the fancy gizmo stuff can stop the wheel spin and basically re balance the power left vs right. He explained that his really old Gwagen was a gem in the really snotty slick snowy stuff that when turning left or right it had equal capability to keep things square and happy. He got a new Gwagen which had all the fancy new techno stuff and more gears and such and he said it actually is easier to break loose turning one way vs the other way to the point driving them back to back he said its very very clear that the new Gwagen system is clearly not engineered in a balanced manner like the old machine was.

Each major revision of a model that involves updated drive systems / suspension changes etc can really change how balanced or not so balanced the AWD system behaves in the whole left vs right power delivery factor for the good or the bad the new fancy nanny systems can suppress this unbalanced nature of the drive systems by limiting wheel spin via ABS and wheel speed sensors etc.

 

[AxleIke]

Jacked up 4x4's with wide tires are, in most cases, more dangerous in slippery conditions than FWD cars, in my experience.

Too true, though here in the CO front range, I find the combination of the two is when things get really bad. FWD car with cheap/bald tires cannot move forward, or does so at an incredibly slow pace. Jacked up 4x4/giant pickup/SUV get pissed, try to overtake or go around, FWD car panics, crash ensues, traffic is at a standstill for hours.

The comment about 4wd making you GO, but nothing else was spot on. They don't call it 4 wheel stop

 

[libarata]

Folks with mudders are also really fun to watch in deep snow. They assume they can go, and even turn at speed! Sipping is around for a reason!

 

[carbon60]

Folks with mudders are also really fun to watch in deep snow. They assume they can go, and even turn at speed! Sipping is around for a reason!

I thought sipping was for hard surfaces, like ice, in order to channel away the water and let the rubber make contact? I always thought mud tires did better in *deep* snow, while snow tires did much better on cleared roads. (Never had mud tires to compare against.)

 

[libarata]

I thought sipping was for hard surfaces, like ice, in order to channel away the water and let the rubber make contact? I always thought mud tires did better in *deep* snow, while snow tires did much better on cleared roads. (Never had mud tires to compare against.)

Sipping will help once you dig down to a harder surface, try to stop, or if you spin your tires a bit and make your own ice. I should be more specific. The folks with the uber wide mudders trying to maneuver at speed(think freeway, or at a quick trot). I was raised to understand that unless you live somewhere where you receive snow that is never cleared for months at a time, you don't want to float(which includes airing down very wide tires). I am solely speaking of on road, and folks who fail to slow down. Sure mud tires will help a but, but only because of the aggressive tread. Any AT tire worth the rating will do just as well, but will give better handling at respectable travel speeds. YMMV.

Also, for what I am now learning, all season tires are not made for fecking winter!
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FYI, it is siping* haha

http://www.google.com/url?sa=t&rct=...eq0glotTY-AgJbcnT-HOq5g&bvm=bv.85761416,d.aWw

Siping increases surface area, which is the point of 'aggressive' tread. It may not help in powder too much, but in easily packed snow, I have always had a good experience with siped tires, over the next fellow with mudders.
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http://www.snowtrek.org/tire-siping/tire-siping.php

 

[carbon60]

Yeah, that's about what my understanding was. I have Duratrac's on my 80 and they work very well in most conditions, but not so much in deep snow on the trail. Can't have it all, as they say.

 

[libarata]

I am taking a huge guess, but in ottowa, you have dry snow right?

 

[carbon60]

I am taking a huge guess, but in ottowa, you have dry snow right?

In Ottawa, we have the pleasure of getting just about every single kind of weather you can think of. Last year, we set a record high and a record low within 5 days of each other.

So yeah, all kinds of snow.

A.

 

[libarata]

Gotcha!

 

[96r50]

I wouldn't sweat it. Tires are going to be your biggest determining factor in winter handling. FWIW, I don't notice any substantial difference between my past 80 () or Subaru and my current part time 4WD 4Runner or Ford pickups that can be traced to the drivetrain. Proper winter tires on the other hand have always made a noticeable difference in winter driving as I'm sure you're well aware!

I currently drive an 80.

I'm wondering if there is any real performance difference at highway speed, in snow or on icy patches, between a vehicle with a centre diff (like my 80 or my previous Impreza or a 4Runner) and a vehicle with part-time 4WD (like most American pickups and the Tacoma). Basically, I'm looking to remove that factor from my personal vehicle choice grid, if it is unimportant.

Thanks,

A.