Winter vs Summer tyres on X-drive

[nick325xit 5spd]

Originally Posted by Bdc101

There are not many good tests of winter tires vs all seasons in non-snowy conditions, but here is a good one that demonstrates that studless winter tires are often much better than all-seasons in wet conditions, as long as it is not super hot:
https://www.edmunds.com/car-reviews/...vs-summer.html

It's not close either, the studless tire significantly outpaces the all-season in the dry. And in this test they use three tires of similar quality from the same manufacturer. For this reason I use both true summer tires and studless tires on my family car, though I have struggled to find a good summer tire for my X.

1) That test is from a long, long time ago. The HX MXM4 was a pretty mediocre tire when it was new, and it was old even then. TireRack tested it in 2005, which implies a release date before then. (I'd guess 2004.) The Primacy Alpin that they tested it against was several years newer. (Yes, I've driven on it. And it barely outpaced the Goodyear RS-A in TR testing, and that tire SUCKED.)
2) All season tire development has moved a *lot* from the state of the art in 2009. (Or the state of the art in ~2004.)
3) Frankly, I don't think that studless winter tire technology has advanced nearly as much as A/S technology has in the limited number of really good A/S tires that are out there.

My gold standard for all seasons is the Continental DWS line, as well as the Michelin Pilot Sport A/S line. They are *nothing* like the shitty touring tires that most people define A/S tires by. Are there other equivalent tires? Maybe a few. Not many, though. These tires are proof that A/S tires can be usable in the snow, good in the wet, and good in the dry.

[nick325xit 5spd]

Originally Posted by andrewwynn

The principle that makes ice slippery is nearly identical to what makes oily roads slippery.

Driving my Z28 with 255/55/16 fantastic summer tires felt like driving on wet leaves in Chicago.

Driving on sp wintersport 3d is amazing on almost any surface.

I'm sure they get gooey over 70-80F and I take special effort to drive less when it's over 80f out.

That said the grip gets better down below 50 and starts to blow away the competition when it's below 20F. I drive plenty right at freezing and the grip is stunning on frost covered roads.

I parked in a puddle once to come out with the tires Frozen in 3" of ice. Drove right out without spinning the tires.

I'm planning to take a couple before and after videos with wife's 50i when I get the winters on.

My car can't break traction with the SPs on unless it's actually snow or ice. I can launch full throttle on snow and it squirms a bit but it's quite remarkable the level of acceleration.

Anyhow back to laws of physics.

Sipes give you grip when there is a thin film on the road. That film can be water oil or frost on concrete.

I happen to live in a "Goldilocks" latitude where I can take advantage of my unique situation.

I have driven on extremely good summer tires and on really crappy all season tires.

I'm sure I could given enough effort find some decent "all season" tires that would get me though winter but I did get horribly horribly stuck with decent "all season" tires in some very deep snow where I wouldn't have even been concerned with the SP.

(I have gone cross country with 7" of fresh wet snow as another example of SP winter sport capability). Zero chance I wouldn't have been stuck in the back yard had I tried that with all season tires.

It's funny. It was a direct comparison of the original DWS to the Wintersport 3D in the same snow storm that sold me on the DWS as a passable winter tire.

Also, I think that it's worth categorizing "performance snows" separately from serious snows. There is absolutely no comparison between the snow traction offered by the Wintersport 3D and, say, the similar vintage Graspic DS-3.

[bcredliner]

If one is North of the Mason Dixon line, with several months of snow and ice, snow tires are likely worth the expense. If you are South of the line, in Texas for instance, they would be useful about 1 week a year. The safest tires for Texas are tires that won't leave home until that week is over. I don't go out because of other drivers and most importantly because the roads are treated with sand and a salt slurry in DFW area.

Much of getting around 'safely' in the winter regardless of ones location has to do with driving style and ability. In most circumstances slowing down, planning to stop earlier, slow acceleration and backing off more car lengths than usual is enough.

In all the controlled tests I have read winter tires are best for snow and ice and in some circumstances wet roads. The more severe the weather the greater the benefit.

All weather tires are a compromise for both summer winter driving. However, I see no value or benefit of running summer or winter tires on an X5 in Texas. An X5 is a good handling SAV but is not a sports car. I can scare myself enough on all season tires in the summer and having the ability to go faster around curves with an X5 would only make a danger to myself and others.

Here is one controlled test on ice: https://www.motortrend.com/features/...ires-worth-it/ Note that even controlled data varies by vehicle. Even sticking to only X5s, which is the best thing to do here, engine and electronics associated with handling, acceleration and stopping by year will vary.

[X5chemist]

Buying tire based on.....

[andrewwynn]

I've never seen a test on oily or wet leaves. That's where my winter tires have saved my bacon.

Absolutely can't use year 'round below about 43°

[bcredliner]

Originally Posted by andrewwynn

I've never seen a test on oily or wet leaves. That's where my winter tires have saved my bacon.

Absolutely can't use year 'round below about 43°

Why not?

[nick325xit 5spd]

Originally Posted by andrewwynn

I've never seen a test on oily or wet leaves. That's where my winter tires have saved my bacon.

Absolutely can't use year 'round below about 43°

The Conti DWS is pretty close in snow performance to the Wintersport 3D. Yes, the DWS is exceptionally good in the snow for an all season. (Also, in my experience, the Wintersport 3D is one of the worst winter tires in the snow that I've driven on. I would actually say that the 3D is more of an all season than a winter tire.) So... I'm very comfortable with the DWS in temperatures quite a bit lower than that.

Hell 43 degrees is a bizarre temperature threshold. That's roughly where aggressive summer tires start getting sketchy.

[andrewwynn]

Why not use year 'round below 43° latitude or why not a test on oily surface?

First one is the rubber gets super soft above 50°F so they will shred and three tread blocks will turn "squishy" and you lose overall control.

Second one, I would love to see a test of summer, winter, "all" season on realistic copy of oily city streets.

For those skeptics out there, find a very high traffic feeder street like what goes to a high density neighborhood and when it's safe with no cars around, panic stop from 35-40 mph.

On dry ground it will take substantial pedal effort to get abs too kick on.

With summer tires on oily surface it will take HALF the effort to skid the tires.

With my studdless tires it takes 80-90% of the dry road pedal effort to engage abs. Enough that it's extremely rare even when the road is wet to engage ABS on a panic stop.

It costs more to maintain two sets of tires than one set of winters including the faster summer wear as long as the similar conditions are met as described for my case.

When ABS kicks on it greatly increases stopping distance. I first discovered this in my Z28; at least 30% longer stopping distance when on slippery surface and all season tires. (never had snow tires on that car and summer tires; pointless in snow; couldn't drive over a 1" bump of snow, not an exaggeration)

When the road is wet, I can just barely get abs to kick on if the roads are clean, but at perhaps 50% brake pressure, no problem on oily+wet to get abs to kick on even with studdless tires.

I have wife's e70 today with the "all seasons". I will see if I can get a g-force reading on a couple example streets where I can recreate the situation once I get the new tires on. I would love to show objectively what I've been describing.

I'm acutely aware of the difference in grip largely in part due to the change in grip of the same model tire at end of life.

When the tread is almost gone the sp winter sport turn into all season tires automatically as the sipes aren't the full depth of the tread blocks. They get slippery on wet just like all season tires. Exchanging for new I get the amazing grip back.

I drive more at 60° and below than above, that is a key to my decision to run on winters only.

[andrewwynn]

Originally Posted by nick325xit 5spd

Hell 43 degrees is a bizarre temperature threshold. That's roughly where aggressive summer tires start getting sketchy.

43° latitude.

[nick325xit 5spd]

Originally Posted by andrewwynn

Why not use year 'round below 43° latitude or why not a test on oily surface?

First one is the rubber gets super soft above 50°F so they will shred and three tread blocks will turn "squishy" and you lose overall control.

Second one, I would love to see a test of summer, winter, "all" season on realistic copy of oily city streets.

For those skeptics out there, find a very high traffic feeder street like what goes to a high density neighborhood and when it's safe with no cars around, panic stop from 35-40 mph.

On dry ground it will take substantial pedal effort to get abs too kick on.

With summer tires on oily surface it will take HALF the effort to skid the tires.

With my studdless tires it takes 80-90% of the dry road pedal effort to engage abs. Enough that it's extremely rare even when the road is wet to engage ABS on a panic stop.

It costs more to maintain two sets of tires than one set of winters including the faster summer wear as long as the similar conditions are met as described for my case.

When ABS kicks on it greatly increases stopping distance. I first discovered this in my Z28; at least 30% longer stopping distance when on slippery surface and all season tires. (never had snow tires on that car and summer tires; pointless in snow; couldn't drive over a 1" bump of snow, not an exaggeration)

When the road is wet, I can just barely get abs to kick on if the roads are clean, but at perhaps 50% brake pressure, no problem on oily+wet to get abs to kick on even with studdless tires.

I have wife's e70 today with the "all seasons". I will see if I can get a g-force reading on a couple example streets where I can recreate the situation once I get the new tires on. I would love to show objectively what I've been describing.

I'm acutely aware of the difference in grip largely in part due to the change in grip of the same model tire at end of life.

When the tread is almost gone the sp winter sport turn into all season tires automatically as the sipes aren't the full depth of the tread blocks. They get slippery on wet just like all season tires. Exchanging for new I get the amazing grip back.

I drive more at 60° and below than above, that is a key to my decision to run on winters only.

I've used at least half a dozen different winter tires, all from new. I'm just saying that the Wintersport 3D was the worst in the snow of all of them. They trade snow traction for dry performance, which is probably why you like them so much as an all season. Because they really are basically an all season.