4-Wheel Drive or Snow Tires?

[Monique]

I just ignore the little tire symbol for 5 months. Electrical tape will cover it up. Just changed to the summer tires. AWD Equinox. Not sure what the snows are for brand. Driving is much quieter now though.

That's fine if you will quickly notice when one goes flat. I can be a bit ... inattentive. The TPS does what it's supposed to do.

 

[tball]

What’s a “snow tire”?

https://www.nokiantires.com/winter-tires/nokian-hakkapeliitta-9-suv/

With studded Hakkapelitta's I drive around in rear wheel drive in a truck with no traction control and no weight in the bed. They don't slip and I don't get stuck. I manually put it in four wheel drive maybe 10% of the time but don't really need to unless I'm in over a foot of snow.

I've tested starting on the exact same steep incline in our neighborhood against our AWD with good all season tires. My truck in RWD with those studs can climb the hill that the AWD with very good all season tires can't.

It's the tires.

In 4x4 with the studs, I've cut first a path in well over three feet of snow when no other vehicle in the neighborhood could get out, including a number of raised 4x4 trucks with AT tires that got stuck. I pulled them out.

Then there is this:
https://www.pugski.com/threads/no-f...es-isnt-good-enough-for-colorado-skiing.1137/

I doubt any vehicle without really good studded tires could have pulled that car up Loveland Pass in those conditions, regardless of drivetrain.

 

[Jilly]

That's fine if you will quickly notice when one goes flat. I can be a bit ... inattentive. The TPS does what it's supposed to do.

Touch wood, 5 years never had problem. But I check the truck before I go on a 4 1/2 hr trek. I if I had a flat....that's what I pay CAA for.

 

[James]

View attachment 45199
https://www.nokiantires.com/winter-tires/nokian-hakkapeliitta-9-suv/

With studded Hakkapelitta's I drive around in rear wheel drive in a truck with no traction control and no weight in the bed. They don't slip and I don't get stuck. I manually put it in four wheel drive maybe 10% of the time but don't really need to unless I'm in over a foot of snow.

I've tested starting on the exact same steep incline in our neighborhood against our AWD with good all season tires. My truck in RWD and those studs can climb the hill that the AWD with very good all season tires can't.

It's the tires.

In 4x4 with the studs, I've cut first a path in well over three feet of snow when no other vehicle in the neighborhood could get out, including a number of raised 4x4 trucks with AT tires that got stuck. I pulled them out.

Then there is this:
https://www.pugski.com/threads/no-f...es-isnt-good-enough-for-colorado-skiing.1137/

I doubt any vehicle without really good studded tires could have pulled that car up Loveland Pass in those conditions, regardless of drivetrain.

How are the studs on the dry or wet pavement when it's not snowing? Like say a 2 hr trip on the highway.

 

[tball]

How are the studs on the dry or wet pavement when it's not snowing? Like say a 2 hr trip on the highway.

They are fine if you can live with the road noise. They handle great. I'm also a little more careful about braking distance.

I'll often do day trips skiing on dry roads with my truck. 1.5 hours each way doesn't bother me with the studs, but I'm used to them as I've had studs forever.

That said, our two vehicles that get driven mostly on the front range have Xice for the winter rather than studs. Other than the pain in the butt of switching them out, there is little downside to the Xice. There's a decrease in dry performance and handling that is negligible if you don't push them.

 

[princo]

They make those Nokians in a truck tire? What size did you get? My sense is that once you have a vehicle that big car tires don't survive well.

As a different point of view, I have the Nokian Rotiiva AT Plus (LT C Load 275/70/17, 17/32" thread depth) in my 4Runner (Full Time 4wd) and they were excellent this last winter. Didn't feel the ABS kick in and didn't even have to lock the center diff or enable ATRAC. They are super quiet on the highway too, and decent in light off road.

 

[Tom K.]

I am actually considering thse for the Alltrack next season. I am limited to what is available in 17" options. I think I have to jump to a 215 from the 205 that comes standard.

Imagine what those wider tires will do for your autocross times, though!

It depends on the system. Subaru still uses a center differential, but the Highlander does not and AWD is electronic fakery. This is true of most AWD, because a center diff has a space penalty and that means less cup holders.

AWD Highlanders and Siennas use a magnetically coupled center differential, which resides right where the spare tire for the FWD models lives.

Which is moderately irritating, since carrying a spare is out, or annoying, at best.

 

[Nathanvg]

I run worn snows down to the wear bars in the summer. Might as well use em up.


4WD helps you steer and brake as well.

Static friction is greater than kinetic friction. That means you have more traction when the tire isn't slipping, and once slipped, it's harder to regain. 4WD keeps at least 1 wheel in the front and one wheel in the back turning. If the excess torque (above slippage torque) is minimized by feathering braking or the gas pedal, the skid can be managed/avoided. With good feathering all 4 wheels keep contact by not driving the differential into differentiating.

Example:
2WD brake in a straight line, apply brake, all 4 wheels skid. Driven wheels slow down and non-driven wheels lock up. When you get off the brake the non driven wheels may still skid as there is insufficient traction to spin the wheels back up to vehicle speed.
4WD: brake in a straight line, apply brake, all 4 wheels skid, however they are still spinning just below vehicle speed. The direct connection to the engine keeps the wheels rotating, they all can't lock up unless you jam the brakes so hard you stall the engine. (Stick shift) If you get off the brake you can re-establish tire/snow contact and regain control. An automatic compromises this effect as you don't have a direct hard connection from the wheels to the engine..

In turns, even though the front wheels may slip, driven front wheels will still pull you into the turn if you feather the gas. In 4wd the rears provide added boost to keep the vehicle moving.

Note that I'm talking snow, not black ice. Real glazed ice on the road generally means you're going for Mr Toad's wild ride. (yeah, yeah, Blizzaks) Worse yet is wet ice - no control.

With the advent of ABS braking control has been taken away from the driver in a skid. This is undesirable as when one wheel slips, ABS kicks in even if the other 3 have good traction still. ABS usually increases your stopping distance at the expense of mandated pulsed braking to salvage steering for a panicked driver.

So in snow,

Stick > automatic
4WD > AWD
AWD > FWD
FWD > RWD
No ABS > ABS (for a skilled driver)
Snow tires > All season tires
Fresh tread > worn tread
Subtle changes > Texas stomp

This leaves a zillion combinations where arguments can be had over which is better. That said, I'll take my 4WD snow tire shod, stick shift, high clearance truck over almost anything else in snow. I've been in snow deep enough to roll waves of snow over the hood.

For inexperience snow drivers, go out and practice. Turn big slow donuts in a parking lot in the snow, building speed until you feel the wheels start to slip. Play with holding that speed and managing the speed and turn at the slip threshold. Try some skidded turns and regain steering control by widening the turn and easing off the gas. Get up to 25mph and then experiment with braking, applying brakes slowly increasing brake pressure until you feel the wheels slip. Ease off just a little until you feel the wheels re-engage. Find the maximum stopping force you can apply. Learn to feather, ie small adjustments constantly adjusting to suit the response. When going up a hill in a snowstorm, try goosing the gas until the tires slip and then ease off. That's your maximum torque available to get up the hill, and you might need it at the steepest part. Momentum is your friend up hills and your enemy down hills.

Small losses of traction is information. Massive loss of traction and massive corrections lead to loss of control. Leave huge space between you and the next car.

Clearly a lot of though has gone into the above explanation, including a lot of good points about practicing and good tires being very important. The basic physics is also accurate. However, I disagree with the conclusion regarding 4WD breaking differences. A few thoughts:

• ABS in modern cars does not pulse or interrupt breaking on all wheels when one slips. Most cars pulse only the wheel that slips. (some cars pulse the left-front, right-front or both back if only one wheel is slipping) So even if one real tire is slipping, you'll still have the other 3 breaking uninterrupted and the front tires apply 75-90% of the breaking (the minimal effect of the real tires is why some cars group the back wheels together)
• Real wheel sliding is much more dangerous than front wheel sliding. As a result cars are designed so that the front slides first. This design takes into account the idle speed force of in a 2WD car. The system varies in each car but one common approach is a "load sensing proportional valve" which puts more breaking in the front first. This front braking emphasis is particularly important since a car lists forward in breaking, with the front breaks typically providing 75 to 90% of the breaking. In snowy conditions, this system can break down due to big differences in friction coefficients on each wheel (traction) but ABS will prevent lock up and ABS will not pulse the other 3 wheels
  
• You don't have to lock up the wheels to slide. As soon as any wheel starts to move slower than the ground below it, the tire will slide (kinetic friction). That means that a car going at 30MPH will slide when the tire is at 29.9MPH and continue sliding well before the car stalls at somewhere around 15MPH. Therefore, it's hard to image any breaking benefit in the above scenario. You might argue that wheel lockup may be prevented in some scenarios which could help with steering but that would also be true for any modern car with ABS.
  
• I did look for studies/test that prove or disprove 4x4 breaking impact and there appear to be a lot of unofficial studies with conclusions both for and against 4x4 breaking advantages.

I don't hate 4x4/AWD. I even own one. I also commonly drive 2WD in the mountains. 4x4/AWD really only helps to keep moving or if you get stuck.

 

[nay]

View attachment 45199
https://www.nokiantires.com/winter-tires/nokian-hakkapeliitta-9-suv/

With studded Hakkapelitta's I drive around in rear wheel drive in a truck with no traction control and no weight in the bed. They don't slip and I don't get stuck. I manually put it in four wheel drive maybe 10% of the time but don't really need to unless I'm in over a foot of snow.

I've tested starting on the exact same steep incline in our neighborhood against our AWD with good all season tires. My truck in RWD with those studs can climb the hill that the AWD with very good all season tires can't.

It's the tires.

In 4x4 with the studs, I've cut first a path in well over three feet of snow when no other vehicle in the neighborhood could get out, including a number of raised 4x4 trucks with AT tires that got stuck. I pulled them out.

Then there is this:
https://www.pugski.com/threads/no-f...es-isnt-good-enough-for-colorado-skiing.1137/

I doubt any vehicle without really good studded tires could have pulled that car up Loveland Pass in those conditions, regardless of drivetrain.

Now we’re gettin’ somewhere. When did it snow well over three feet in Denver?

I love studded tires, although they don’t do anything except on ice, where there is studded and everything else. All that stuff about bad handling on dry pavement - meh.

I was on Loveland Pass that day of the ground blizzard skiing A-basin. That little car would have been no issue except it probably lacks tow points.

This is a snow tire.

 

[Alba Adventures]

Artic Altimax studded snows. We have a SAAB wagon - low clearance - only got stuck up the hill to our driveway last season 1 or 2 times as the snow was to deep.

 

[nay]

AWD Highlanders and Siennas use a magnetically coupled center differential

It’s not a center differential. It’s a coupler attached to the rear differential controlled by the ECU that is essentially a series of clutch packs that force power to the rear axle by electronic engagement “coupling” the rear driveline. That’s what I meant by electronic fakery.

Like any clutch system, it’s ability to “grip” can be overcome by loss of traction so it’s only a biasing system integrated into the driveline between the transmission and rear axle.

These systems are pretty widely used because of the ability to configure the drivetrain without regard to input and output of a center diff along with weight and space savings, but they are pretty well acknowledged to be less effective and there is no AWD unless the coupler engages.

In other words, this is a FWD car with an electronically managed clutch system designed to mimic a center diff, but there are limitations to how effectively this can work. Subaru put out a video testing various AWD systems by putting tires on rollers simultaneously. IIRC the Toyota system struggled once two wheels had no traction and it could not handle 3 wheels with no traction at all, whereas the Subaru with the center diff could.

 

[tball]

Now we’re gettin’ somewhere. When did it snow well over three feet in Denver?

I love studded tires, although they don’t do anything except on ice, where there is studded and everything else.

It was the big one back in March of 2003 when my truck was just a pup. I had studded Firestone Winterforces, which suck in comparison to any decent snow tire today. They did have wide lugs which helped with the deep snow. They were much better snow tires than ice tires, even with the studs.

I generally agree about studs being primarily for ice. I do think they help some on hardpack. I also think studs can help get you unstuck when you do something stupid and your wheels are spinning and creating patches of ice under each wheel.

Edit: we'll have to resolve this with a good old tug of war on snow!

 

[pete]

Artic Altimax studded snows. We have a SAAB wagon - low clearance - only got stuck up the hill to our driveway last season 1 or 2 times as the snow was to deep.

agree on the Artic Altimax especially given price. bit meatier tread pattern that's worked great on a Silverado. Given they're 265/70 R17 were around $fthe set. Got the Ice-x on other car, they're really great but not as good for deep snow - and much more pricey.

But both way better than very good all seasons, esp touring.

 

[nay]

It was the big one back in March of 2003 when my truck was just a pup. I had studded Firestone Winterforces, which suck in comparison to any decent snow tire today. They did have wide lugs which helped with the deep snow. They were much better snow tires than ice tires, even with the studs.

I generally agree about studs being primarily for ice. I do think they help some on hardpack. I also think studs can help get you unstuck when you do something stupid and your wheels are spinning and creating patches of ice under each wheel.

Edit: we'll have to resolve this with a good old tug of war on snow!

You couldn’t have paid me to run an AT back in ‘03 - they all froze up in cold temps and were useless. The gap was much larger then.
A tug of war on snow would be excellent . We could also invite some Subes.

When I win lotto I will run a studded 37” in winter. They are hard to come by, although Kanati (a brand of Greenball who makes tractor, military, and ATV tires) has put out a good heavier duty copy of the Duratrac that is studdable, comes in a 37”, and only costs about $240 a tire.

Winter rated. That would be the bees knees for a deep snow and ice tire.

 

[François Pugh]

Everybody's got an opinion, and some won't be changed by the facts. Here's mine.

The new snow rated all-weather all terrain tires may be the best compromise between traction and convenience, but the tire with the most traction in snow and ice is the tire designed to be so by the tire company who invented snow tires. In an emergency stop or avoidance maneuver, you will stop faster and avoid better with the studded Hakkapallita SUV 9 on your SUV instead of those new all terrain tires - regardless of drive train.

Is it worth the the traction you give up on dry warmer pavement? Well, why are you buying a winter tire in the first place?

BTW, studies have shown the fastest way to stop in loose gravel or deep wet snow or deep sand is to lock up all four wheels and dig some trenches.

 

[scott43]

What do the studies say about 58 year old people with a coffee in their hand trying to modulate brakes on the highway in the rain???? There's a reason why the assumed reaction time for highway design is 3 seconds... Like I say, Formula 1 drivers!

 

[Monique]

It was the big one back in March of 2003 when my truck was just a pup. I had studded Firestone Winterforces, which suck in comparison to any decent snow tire today. They did have wide lugs which helped with the deep snow. They were much better snow tires than ice tires, even with the studs.

Pssh. That was the storm I mentioned above, when I drove from Boulder to Broomfield in a Celica GT - front wheel drive - with basic all seasons. I remember watching all sorts of pickup trucks spinning off the road on 36.

Granted, there was less snow in Boulder and there was progressively more as I headed toward Broomfield - otherwise I doubt I would have tried.

 

[tball]

The new snow rated all-weather all terrain tires may be the best compromise between traction and convenience, but the tire with the most traction in snow and ice is the tire designed to be so by the tire company who invented snow tires. In an emergency stop or avoidance maneuver, you will stop faster and avoid better with the studded Hakkapallita SUV 9 on your SUV instead of those new all terrain tires - regardless of drive train.

Is it worth the the traction you give up on dry warmer pavement? Well, why are you buying a winter tire in the first place?

Agreed. Tires keep you alive. Drivetrain keeps you from getting stuck. I'm more worried about staying alive.

I do think studs or not depends on your particular usage. I have studded Hakka's on one vehicle and X-ice on two others.

No doubt the studded Hakka's are better. Hakka's are on my vehicle for powder chasing into the storm in the very worst Colorado mountain road conditions. It's also a truck that spends most of its time in RWD and doesn't have stability or traction control. It's very dangerous if I lose the rear end. With the studded Hakka's, that only happens in a controlled fashion. Note it does have ABS, which I would never drive a vehicle without regardless of tires. The ABS not needed often with those tires, but it's great when you need it.

I love the X-ice's for our family AWD SUV and RWD sports sedan. They make the SUV a fantastic family ski vehicle to drive in any conditions, while most of its miles are on dry roads in Denver. They make the RWD sedan very much snow worthy, even better than an AWD with all-season tires. Before we had the X-ice's for the SUV, my wife preferred driving the RWD sedan in the snow tires over the AWD SUV with all seasons. It's really nice to be able to turn and stop!

 

[tball]

Pssh. That was the storm I mentioned above, when I drove from Boulder to Broomfield in a Celica GT - front wheel drive - with basic all seasons. I remember watching all sorts of pickup trucks spinning off the road on 36.

Granted, there was less snow in Boulder and there was progressively more as I headed toward Broomfield - otherwise I doubt I would have tried.

IIRC, it was a multi-day storm. By the end of it, 36 was an unpassable parking lot of stuck vehicles. The National Gaurd had to pick everyone up in Humvees and take them to shelters the next morning. I remember seeing an interview of some commuters who spent the night on an RTD bus

Throughout the storm, I was driving around pulling vehicles out with my new Toy. By the end, it was clear most were never making it home. I ended up pulling the vehicle to a safe spot then giving them a ride home. That was the first time a car seat was in my truck when I gave a mom and her infant a ride home!

 

[tball]

The worst part of that storm is you couldn't get up skiing. Every road was closed for days!

A good summary from the Washington Post:

When the sun finally came out Thursday, the National Weather Service reported 31.8 inches of snow in Denver, the most since a five-day storm in 1913 dropped 47.5 inches. Boulder got 22.5 inches of snow, Fort Collins 28 inches, Golden 50 inches, and Evergreen, the upscale suburb in the foothills west of downtown Denver, recorded 73 inches.

But the overall record for inhabited areas was claimed by the mountain hamlet of Rollinsville, about 30 miles west of Denver. The village's elevation rose (temporarily) from 8,700 feet to 8,707.3 after 87.5 inches of snow fell from Monday through Wednesday. Since nearly all the 160 residents own cross-country skis and snowshoes, Rollinsville took the daunting dump in stride.

The Colorado ski resorts, which run big advertisements when they get just six inches of new powder, were wallowing in white stuff.

Winter Park resort reported 120 inches of new snow at the summit; Vail had 68 inches, Breckenridge 74 inches, Copper Mountain 76 inches. Aspen, to the south and west of the main tranche of the storm, reported 16 inches, a total that would be formidable most of the time but barely registered last week.

The problem for skiers and ski areas was that Interstate 70, the highway linking Denver and its airport to the ski resorts, was closed much of the week, either by stranded cars and trucks or by avalanches. Hundreds of would-be skiers spent their spring vacation at motels and gas stations, gazing in frustration at the snowy slopes they couldn't reach.
https://www.washingtonpost.com/arch...6ba-846f-ab4705c32165/?utm_term=.4dac2c16105a​