Advantages of AWD in snow?

[Bill Talbot]

AWD in general will increase traction. Allows you to get going on slick surfaces, and go up hills. It does nothing to help you stop or turn.

As has been hinted at, all AWD systems are not created equal. Some simple systems run as FWD untll slipping is detected, then some power is sent to the rear wheels. Others are full-time and have sophisticated systems that control where the torque and power is going based on multiple inputs. Some also improve handling on clear dry surfaces with features like torque vectoring.

I've spent over five decades driving in the mountains in New England in the winter. I've also had FWD, RWD and AWD vehicles over the years. I am a big fan of an AWD vehicle with a good AWD system and good tires.

I wish folks would stop saying this! It's simply not true.
See post #11

 

[martyg]

AWD in general will increase traction. Allows you to get going on slick surfaces, and go up hills. It does nothing to help you stop or turn.

Unless you have an advanced ststem with torque vectoring.

 

[Snowfan]

If you get pulled into the slop R or L with AWD or 4WD stomp on the gas and steer out. 2wd you're sucked in. Stopped in traffic on slippery hill? No problem AWD 4WD.

AWD and 4WD ONLY forever 4ME.

 

[slowrider]

Regardless of the type of 4x4 system in the vehicle there're driving skillsets that will improve traction and handling. Gear reduction and power braking for descending grades is a must to controlling a vehicle. Same with pulling grades. Sometimes it's easy on the throttle, other times you have to Rambo it up a goat trail.

 

[scott43]

I wish folks would stop saying this! It's simply not true.
See post #11

In theory it's not true, in reality it is.

 

[scott43]

Unless you have an advanced ststem with torque vectoring.

It won't help decrease stopping distance necessarily, but it'll keep you straight more or less and give you the best chance of achieving the shortest possible stopping distance. Especially for your average driver.

 

[oldschoolskier]

Nah, that's what 4WD low is for!

Just to get stuck another 10 feet further in , unfortunately speaking from experience.

 

[Bill Talbot]

In theory it's not true, in reality it is.

It is using more of the AVAILABLE traction, not making more of it.

 

[François Pugh]

Semantics.

If you have a wheel pushing with a force of X Newtons, limited by the available traction between the tires and the snow, you have half as much force pushing you ahead than you would have if you had two wheels pushing with a force of X Newtons each. People call that more traction.

Also, contrary to popular belief, AWD does help you turn if you are also slowing or speeding up while in the turn. Google traction circle. Spreading the turning force between two axles allows you to turn harder without exceeding the limit of that traction circle. True, the maximum turning force at the APEX does not change, but being able to go faster while slowing on the way in and getting going again on the way out makes a big difference.

 

[PinnacleJim]

I wish folks would stop saying this! It's simply not true.
See post #11

Sorry, but I disagree with you. Maybe it's just semantics, but the more wheels driving at the same time means more thrust to get you moving. I call that traction.

 

[martyg]

Pretty well covered. Studded snows on the SQ5 for drives when it is nuking. Regular snows on the TTRS for cold, dry-ish roads.

That being said, I drive a FWD VW up the snowiest mtn in the world for years with snows. However speed were limited, and little ice.

As others have said, boosting that coefficient of friction with proper rubber is your first step.

 

[pchewn]

Pretty well covered. Studded snows on the SQ5 for drives when it is nuking. Regular snows on the TTRS for cold, dry-ish roads.

That being said, I drive a FWD VW up the snowiest mtn in the world for years with snows. However speed were limited, and little ice.

As others have said, boosting that coefficient of friction with proper rubber is your first step.

View attachment 132732

That's a big dirty fenderberg near your tire. About to hit the ground.

 

[Ogg]

I usually have much to say on the virtues of a good AWD system combined with proper tires but all of my usual arguments have been covered. AWD can definitely help with steering and to a lesser extent, braking if the driver knows how to get the most of it. With a well balanced AWD vehicle and the right tires you can pretty easily do controlled drifted turns that are difficult to impossible with 2wd and recovering when things get squirrelly is easier, IME. That being said you can also get yourself in trouble with overconfidence and good rubber and/or driver experience and skill is more important than AWD.

 

[DanoT]

I remember many years ago, a friend with a Renault Dauphin would go up slick hills backwards for more traction.

IIRC the Renault Dauphin was rear engine, RWD and that would mean the going up hills in reverse would, due to gravity, shift weight to the rear of the car and therefore traction from the front of the vehicle (now the rear wheels) to the rear. So the real reason for backing up steep hills would have been because 1st gear was too high and "R" was the lowest gear.

 

[Bill Miles]

IIRC the Renault Dauphin was rear engine, RWD and that would mean the going up hills in reverse would, due to gravity, shift weight to the rear of the car and therefore traction from the front of the vehicle (now the rear wheels) to the rear. So the real reason for backing up steep hills would have been because 1st gear was too high and "R" was the lowest gear.

You right, of course. I must be misremembering from the early 60's.

 

[slowrider]

I've descended
grades(unassisted)that the motor started pumping oil out the fill spout. About 40-50% grades.

 

[François Pugh]

You right, of course. I must be misremembering from the early 60's.

You know what they say, "If you remember the 60's your weren't there."

 

[sparty]

Just to get stuck another 10 feet further in , unfortunately speaking from experience.

Horizontally or vertically?

Back to the original subject: AWD is often more user-friendly, especially with torque vectoring, for those who don't know (and don't care to know) much about driving dynamics. That makes it a useful tool for a lot of the American populace.

Personally, I consider the ability to mask slipperiness in a straight line a bit of a mixed blessing—it absolutely allows a faster rate of travel, but if I don't notice that the dash light is flashing, it becomes really easy to overestimate how much grip I have. I prefer proper, selectable 4WD in most conditions, because I can (usually) feel the ass end trying to kick out on throttle before things actually go pear-shaped, and I find it easier to recover from a sliding tail end than a steer axle that's decided to choose a different direction of travel. If things get truly slippery, flip the switch into 4WD and continue on (with the clear realization that expecting a lot of cornering or stopping traction is a horrible idea).

The one place I really miss 4WD auto (available on higher-end Fords and, I think, most GM trucks) is mixed surfaces on 50 MPH roads, like coming over a rise on I-90 and going from clear pavement to wall-to-wall ice and snow.

Re: stopping quicker: Team O'Neil did a YouTube video comparing 4WD vs 2WD stops on snow, with the 4WD winning by a significant margin. I don't know if the results would hold up in an AWD system.

 

[scott43]

Those 4wd tests are very specific to certain vehicles and conditions and ignore the real world to some degree. Most people need all the help they can get in a panic situation.

Torque vectoring is cool but electronic brake distribution is also very important for most average people.

I'd say the people who know about AWD and these things will choose what works for them and those who don't are probably better off with the simple safety features most vehicles have now.

 

[sparty]

I'd say the people who know about AWD and these things will choose what works for them and those who don't are probably better off with the simple safety features most vehicles have now.

I'm 99% in agreement. I just wish we could mandate that new drivers start in underpowed 2WD pickups with manual transmissions, but that probably falls in the 'get off my lawn' category of theory.

I do wish I could default my truck to the "sport" mode on the nannies rather than the default mode, which allows a reasonable amount wheelspin until the steering angle goes out of center and then cuts power pretty quick. It makes attempting to steer with the throttle a bit interesting, whereas the "sport" mode works pretty well for most transportation purposes (not necessarily all recreational ones).