frontrangeleaf wrote: ↑
Sat Aug 03, 2019 6:09 pm
Hey JJeff, thanks for the welcoming thoughts.
Having grown up outside of Chicago and attended school in MN and WI, I'm familiar. Not running true snows in the winter in the mid-west strikes me as maybe a little odd since icing is pretty common, but I know it's the norm. What I know or think I know about snow tires I have from personal experience and reading too much on Tirerack. Here's my understanding such as it is:
M+S - "Mud and Snow" designation goes back to the old belted bias days, and refers strictly to tread geometry. That is, there is no performance requirement to gain that designation. Nowadays virtually any so-called "all-season" has that designation. As far as I can tell, "M+S" is basically meaningless or nearly so. It's not a racing slick. Good to know, LOL.
"All-season" itself is purely a marketing designation. Depending on the tire, it may well mean "all seasons in Florida..." (hot, dry and wet). As I understand matters, all-seasons are typically optimized for temperatures down to around freezing, but not lower. I regard all-seasons as basically 3 calendar season tires depending on where you live. Might be less in Canada for example. Any tire rated for dramatically long mileage is suspect in the slick.
The "3 peak mountain snowflake" symbol to which you refer, on the other hand, is a "severe winter service" rating associated with a tire providing at least 15% more traction in a linear direction (when braking and accelerating, not laterally in a corner, that is) when compared to a reference tire under lab conditions. These tires are optimized for temperatures as low as 0 degrees as I understand matters. They are the tires to which I was referring in my OP. I am looking hard at the Michelin X-ice3s. Great tire (I've had them on a different car), and also efficient. I'll prolly go with a 205/55R17 on our stock wheels. Narrower is better on a snow tire. Just a touch taller doesn't hurt either.
True snows employ a whole range of technologies to get grip under lousy, slippery and cold conditions, beginning with the rubber formula, extending into silica (sand) particles embedded in the tread, micro pores to pump water off the tread, and on and on. They are a different animal, but tend to wear quickly under warm temperatures because they are formulated to stay softer and more compliant under cold conditions, so that they can grip microscopic irregularities on the road surface. In Colorado, it is now illegal to drive on tires inappropriate for winter conditions when the "chain law" goes into effect in the mountains (whenever winter storms hit, basically). So many people were driving on iffy tires in the winter time and causing accidents and traffic jams during ski season, that the chain law for big rigs was extended to all vehicles. The fines for causing an accident on bad/inappropriate tires when the chain law is in effect are steep. I gotta say, I'm OK with that. The mountains are no place for iffy tires in the winter time.
Pure "summer" tires, on the other hand, are not rated for temperatures below 45 degrees Fahrenheit. They are definitely inappropriate and even dangerous in winter conditions. I'm not surprised you had bad experiences with the tires you got used from SoCal. Our Q came with them originally, which I was OK with, since we bought dedicated snows for it as soon as winter broke.
I have since replaced those original summers with a high quality "ultra-high performance all-seasons" - which I'm pretty sure is more marketing mumbo jumbo, aka a contradiction-in-terms. They are nice tires, though, and I like them. Conti DWS 06 is the model. I run them as our 3-season tires on all of our cars, the roadster included. Not a summer tire though, to be clear. And OK in the winter, but definitely more about performance in the dry and the wet. I wouldn't recommend them for MN as your only tire. Not likely to use these on the Leaf though, more likely to try the Conti Pure Contact LS for that car. I might go a little wider just for fun. Need to know more about the car first.
One of the problems with getting to a good all-season design that might truly be 4-season is that the things you do to optimize for rain and mileage de-optimize the tread design for snow, and vice versa. In recent years, so-called "all-weather" tires have debuted, first in Europe as I understand matters. I ran one of those on our Tig - a dutch tire from Vredestein called the Quadrac 5. Independent tests show it a step behind full-on snows, but much better than typical all-seasons in winter conditions. The tread design is literally split 1/2 for rain and 1/2 for snow. The Quad 5 does carry the 3 mountain peak/snowflake symbol. There are other all-weather designs coming out every year. Each is optimized slightly differently.
I get what you're saying about storing and paying for extra wheels, etc. Especially with active TPMS sensors (why not passive TPMS using the ABS sensors on each wheel, like everyone else does?), it does get expensive. We do have a lot of hills around here, some of them steep. Investing a bit more in tires that really work when the weather turns is important to us. Once you get past the initial hit, though, you spread your mileage across 8 tires, so that your running expense is about equal. And avoiding just one accident you wouldn't have pays you back with interest. Hence my conviction.
The first time we bought dedicated snows. we put them on our car just before a trip back to Chicago to visit family over Christmas. On the way home, this is years ago, we hit an ice storm on I-76. I'm driving along, and I'm seeing oncoming traffic in the other lane, and those cars are all full of snow and crap. Didn't think much of it. I check for brake grip and wiggle the wheel a bit - everything seems fine. But I slow first to 55 and then to 45 as things get worse. Pretty soon I have folks passing me on the left. 10 miles up those same folks are in the median getting out of their cars, off the road. Everyone looks alright, so we continue. "That's odd," I'm thinking. "Huh." I check brakes and wiggle the wheel again. Everything's fine. We pull into the garage at home an hour later, I open my door to discover almost 2 inches of ice on the car!
That was our first experience with the difference a good tire can make. I have since avoided 2 major accidents on I-70 up in ski country, both severe and unfolding barely 5-6 cars in front of us, because I could. I might also add, I've taken winter driving courses put on by the Rocky Mountain Audi club on frozen Lake George each winter. This is a thing we take pretty seriously.
Another long post, I'm afraid. I'll rein it in going forward.
Hope this helps,