Advantages of AWD in snow?

[snwbrdr]

OK, I'll try one more time.

Traction Circle

www.formula1-dictionary.net

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There are times when you need maximum steering force. If you are braking and steering at the same time, you do not have maximum steering force. Those times are when you have to get your foot off the brake pedal.

ABS prevents your wheels from locking up. There are times when you need your wheels to lock up, for example emergency stop in a straight line on loose gravel or bumper level snow.

You do realize, Formula 1 cars don't have ABS brakes, right?

Remember, ABS is pulsing the brakes, during the periods of the ABS not on the brakes, that allows you to steer in accordance to the traction circle.

WRC rally cars have ABS brakes though. and in addition to Tarmac surfaces, they also drive on loose and slippery surfaces.

 

[snwbrdr]

Anytime the road is slippery awd will be better and safer and faster. Manual tranny is even better. The variable awd i have used is just ok.

If you want to pass the car going 35 mph you want awd.

Back in my FWD days I passed cars going 35 mph, but I had proper 3PMS tires.

 

[François Pugh]

Back in my FWD days I passed cars going 35 mph, but I had proper 3PMS tires.

By FWD, do you mean front wheel drive or four wheel drive?
Yeah, back in my crazy days I passed everything on the road, front wheel drive, rear-wheel drive, 4x4 what-ever. It takes a lot less time to get by with more drive wheels. It might be safer to just hang back though.

 

[slowrider]

First one to the accident.....

 

[scott43]

WRC rally cars have ABS brakes though. and in addition to Tarmac surfaces, they also drive on loose and slippery surfaces.

I haven't followed WRC in a while but I'd be surprised if they were using ABS, except perhaps if it's switchable or limited in some way. Even outside the comp regs I'm not sure they would want to use it except in certain circumstances.

 

[scott43]

First one to the accident.....

AWD is kinda like a circular saw..it's a lot faster at cutting wood but you can also cut your finger off more easily. It's a tool to be used judiciously. In the hands of a skilled driver, you can cut some wood man. As far as traction perception in AWD vs 1WD, you are still able to find the traction level perfectly well..it's just not as obvious to some who aren't very good at driving or who are not familiar with AWD. Again, circular saw...

 

[sparty]

First one to the accident.....

The more cars you pass, the fewer you have to worry about crashing in front of you.

Re: torque in slippery conditions: as others have said, it's mostly about being gentle with your inputs, which is a good idea anyhow. My truck (2017 F-150 w/3.5L turbo) has stupid amounts of power compared to many vehicles from the recent past and, unless loaded up, a huge front-axle bias for weight; the physics are pretty lousy for slippery surfaces. Even in 2WD, it's completely manageable for an experienced and conscientious driver.

If the term "oversteer" sounds like Greek, though, it probably isn't a great vehicle for the snow. My wife has plenty of experience driving in the snow but never any interest in performance driving, so it would probably be a bad snow vehicle for her (or my mom, who borrowed it when her Forester was down and then drove all the way to work in 4WD because she spun the tires a bit leaving the driveway). A good AWD system mostly solves that problem, since they usually respond well enough to gentle inputs and pointing them in the direction you want to go.

 

[slowrider]

The more cars you pass, the fewer you have to worry about crashing in front of you.

That's one way of looking at it. Not necessarily the best however. You never know what's around the next corner. Ask me how I know.

 

[scott43]

The more cars you pass, the fewer you have to worry about crashing in front of you.

Re: torque in slippery conditions: as others have said, it's mostly about being gentle with your inputs, which is a good idea anyhow. My truck (2017 F-150 w/3.5L turbo) has stupid amounts of power compared to many vehicles from the recent past and, unless loaded up, a huge front-axle bias for weight; the physics are pretty lousy for slippery surfaces. Even in 2WD, it's completely manageable for an experienced and conscientious driver.

If the term "oversteer" sounds like Greek, though, it probably isn't a great vehicle for the snow. My wife has plenty of experience driving in the snow but never any interest in performance driving, so it would probably be a bad snow vehicle for her (or my mom, who borrowed it when her Forester was down and then drove all the way to work in 4WD because she spun the tires a bit leaving the driveway). A good AWD system mostly solves that problem, since they usually respond well enough to gentle inputs and pointing them in the direction you want to go.

Most vehicles are designed for your mom and wife. Even high-performance vehicles are fairly well tamed for the hero crowd. Although there are a few truly evil (fun) cars still left...

 

[DanoT]

The more cars you pass, the fewer you have to worry about crashing in front of you.

Yeah and now you are braking for the crash in front of you; this is when you suddenly realize that you are going to stop in time but that RV or big highway hauler truck that you just past will need twice your stopping distance and will likely not stop in time.

 

[scott43]

Yeah and now you are braking for the crash in front of you; this is when you suddenly realize that you are going to stop in time but that RV or big highway hauler truck that you just past will need twice your stopping distance and will likely not stop in time.

This is where motorcycle experience helps..picking safe riding spots..emergency escape routes...watching mirrors when stopping..becomes all built-in behaviour. having said that, you can't mitigate every risk...

 

[slowrider]

This is where motorcycle experience helps..picking safe riding spots..emergency escape routes...watching mirrors when stopping..becomes all built-in behaviour. having said that, you can't mitigate every risk...

Good advice. Drive between the herds. I believe there's a driving ed system called the Smith system that goes along those ideas.

 

[Dave Marshak]

The more cars you pass, the fewer you have to worry about crashing in front of you.

That's my strategy too. Unless you pass everyone, you always end up behind the slowest driver, and usually in a cluster of traffic that is a chain reaction crash waiting to happen.

Yeah and now you are braking for the crash in front of you...

There's some truth in that. You really need to be aware in traffic, and passing safely is not always possible. Still, l prefer to leave the slow crowd with their all season tires behond me.

dm

 

[DanoT]

This is where motorcycle experience helps..picking safe riding spots..emergency escape routes...watching mirrors when stopping..becomes all built-in behaviour. having said that, you can't mitigate every risk...

^^^Reminds me of standard operating procedure for driving on active logging roads, especially on Vancouver Island where you can encounter off highway trucks that because of their size and weight (150-175 tons, loaded) occupy the centre of the road. The SOP is to make a mental note as you drive by a pullout because you never know when you may suddenly find yourself face to face with one of those behemoths and you needing to backup in a hurry to a safe spot. This because while you car may need 150ft to come to a stop, the loaded off highway truck needs more like 300ft to stop if it is going at a decent speed. The math does not work in your favour.

 

[Dave Marshak]

Different question, but any thoughts on the effect of higher torque in snow/ice conditions? Positive or negative attribute? Planning to buy an AWD with a turbo charged engine that produces over 300 lb-ft of torque. I grew up driving in snow so I understand the basics (i.e., importance of tires, abs, AWD doesn't help you stop, etc.) but am not sure how the higher levels of torque will affect handling on snow/ice.

It's all about throttle response. You want a car with a gradual, nmaybe even sluggish, response to your right foot. If the car is too owerful, it's too easy to spin the wheelss, even if you have soft feet. Low torqu horsepower and/or high gears work best.
Turbe doesn't matter anymore. Older turbos were lagging and could kick in at the wrong time. I had an early 80's Mitsubishi turbo that was easy to drive until you git just a little too deep into the pedal and the turbo spolled up. That was exciting.
OTOH we have a 2019 Accord turbo. There's no noticeable turbo lag, but first gear is so low that it's almost impossible to launch without wheelspin in slippery conditions, even if it's only rain. The only way to lock out first gear is to use sport mode, which makes it harder to modulate the throttle. That car really needs snow mode more than sport mode.

dm

 

[scott43]

Mfgs try to make cars feel "peppy" with abrupt throttle response. Meanwhile you can be waiting a long time for a gearshift when it runs out of steam at 4500rpm...

 

[Dave Marshak]

Mfgs try to make cars feel "peppy" with abrupt throttle response. Meanwhile you can be waiting a long time for a gearshift when it runs out of steam at 4500rpm...

QFT.
That was especially true back in the sixties, My slant six Dodge felt like a Corvette for the first 30 feet from a traffic light. European cars were much more linear, and that made them a little easier to drive in snow. Modern cars are all so powerful that there's no need to juice the throttle response.

dm

 

[scott43]

We're in a golden age of horsepower right now...

 

[dan ross]

Agreed with most other points here:

Top notch winter tires are the most important non-driver element (you see a lot of folks in upper New England who drive FWD or RWD cars with full winter rubber and get around just fine in their snowy/icy mess winters)

AWD systems differ wildly, some being the real deal (e.g. Audi, Subaru), other less so (e.g. RAV4 AWD).

Any way you look at it: pilot skill and knowing limitations is the real key. [/QUOTE]

 

[dan ross]

The big assumption here being that the car has an automatic or CV transmission - which (sadly) most modern cars do. Those of us still part of the Cult of the Clutch (or the Three Pedal Army) know that using engine braking is a good thing...

Agreed with most other points here:

Top notch winter tires are the most important non-driver element (you see a lot of folks in upper New England who drive FWD or RWD cars with full winter rubber and get around just fine in their snowy/icy mess

So true and good tires are everything -I’ve drivenAWD, FWD, 4WD ( including manual hub lock!) and All of them had good , season appropriate tires-without them the vehicle is handicapped and the capabilities of the drivetrain are wasted. When I was a kid, my dad would take us to empty parking lots after a storm and have us practice steering out of ( into) a skid -I can’t remember how many times this paid off and kept me out of the ditch or worse.