do stock tires lose a lot of grip in low temps?

[Suberman]

Originally Posted by OICU812

Michelin Pilot Sport A/S if yearly driven are a quality replacement consideration IMO.

I second this recommendation. I put a set of Pilot A/S Plus on my SAAB Aero and they are exceptionally good all season tires. I'll get to try them on ice and snow on Sunday.

The latest version from Michelin is the Pilot A/S 3 which is supposed to be as good as the Pilot PS2 summer tire (itself now superseded by the truly awesome Pilot SuperSports summer tire).

And yes, the stock tire's already questionable grip will deteriorate in colder weather. 60F is not the colder weather the tire makers are referring to. Summer tires work fine down to about 45F.

[YDNA]

you mean the stock tires have grip?

[dsgerbc]

Originally Posted by OrbitalEllipses

I find that once temps hit the 40s, summer compounds start getting sketchy.

Compounds - sure, but it's nowhere near dramatic. Summer tires, which are compound + tread design, will still grip better in the dry than most A/S tires and dedicated winter tires well into sub-freezing temperatures.
It's hard to find tests of this, but there are some, if one's willing to search.
Tires like Extreme Perf Summer will get harder quicker, but will still be better than alternatives in the dry. People do get in trouble on those in temps around 30-40F, but not because the grip is less than with A/S or winter tires, but because they have had so much grip when it was warm and people got used to that.

[OrbitalEllipses]

Originally Posted by dsgerbc

People do get in trouble on those in temps around 30-40F, but not because the grip is less than with A/S or winter tires, but because they have had so much grip when it was warm and people got used to that.

Well of course; it only seems dramatic due to the psychology behind first having OMG GRIP! and then not having OMG GRIP!

Once precipitation starts in freezing or sub-freezing temps, a high tread depth all season will beat out any summer tire IMO.

[dsgerbc]

Originally Posted by OrbitalEllipses

Well of course; it only seems dramatic due to the psychology behind first having OMG GRIP! and then not having OMG GRIP!

Once precipitation starts in freezing or sub-freezing temps, a high tread depth all season will beat out any summer tire IMO.

Sure, precipitation+sub-freezing+summer tires don't mix too well.

[Suberman]

Originally Posted by dsgerbc

Compounds - sure, but it's nowhere near dramatic. Summer tires, which are compound + tread design, will still grip better in the dry than most A/S tires and dedicated winter tires well into sub-freezing temperatures.
It's hard to find tests of this, but there are some, if one's willing to search.
Tires like Extreme Perf Summer will get harder quicker, but will still be better than alternatives in the dry. People do get in trouble on those in temps around 30-40F, but not because the grip is less than with A/S or winter tires, but because they have had so much grip when it was warm and people got used to that.

I strongly suspect Evo tested the dry traction at higher road surface temperatures than 7C. Either that or they got enough heat into the summer tires to skew their results. Their results are anomalous for dry traction in cold weather.

Comparing that Conti 5 to the Kuhmo and Nankang doesn't tell you anything useful, except don't buy Korean or Chinese tires in preference to German.

I don't agree with your remark about the grip difference being due to psychological factors. It is really the case that summer tires don't grip as well on cold pavement. It is easy to find proof, the link you posted shows this, if you understand the qualities of the tires they tested. If you mean a really good quality summer tire might grip better than a craptastic all season tire then, duh, what's your point?

[dem00n]

The Primacy HP's rubber gets pretty shitty below 40, not safe at all. It gets pretty cold at night here ,around 40ish and i lose grip on corners with light throttle, just slight oversteer. Winter tires will go on soon.

[dsgerbc]

Originally Posted by Suberman

It is really the case that summer tires don't grip as well on cold pavement.

Please find a correct test of summer tires on dry winter asphalt, then, not showing summer tires being superior.
Thanks.

If you actually bother to search, instead of 'suspecting', you'll find what I've found. Here's another one for you. It's a bit dated, but the picture is the same. Those Michelin UHP A/S tires are basically summer tires with a bare minimum for winter. They trump every other tire in this test in dry traction at 23F.

Evo's results aren't anomalous, it's just very few outlets test this. But all the tests I've seen of this always say that "summer" tires are better in the dry until VERY cold.

I'm not saying one should drive on summers in the winter, I'm saying
a) there's very little reason to rush the switchover (the 48F/8C 'recommendation' is basically not based on anything) until there's precipitation at sub-freezing temps
b) there's generally less grip when it's cold. Don't expect your "Performance winter tires" to give you the same grip good summer tires give you when it's 90F. Expect your I&S winter tires to absolutely suck in the dry and start braking waaay earlier than usual, and carry much less speed in corners.

That said, my last winter with Xi3s on my BRZ was very fun in the city for that very reason - low dry grip.
This winter I'm driving my BRZ on OEM Michelins unless it's raining, snowing or roads aren't plowed yet. If the roads are clear and the forecast is good, I won't hesitate to dry on OEM Michelins if it's 20F.

Basically, what I'm saying is that summer tires are actually 3-season tires.

[Suberman]

All season tires are defined by their sea/land ratio. There are no winter performance standards, specifications or requirements.

True winter tires bearing the mountain snowflake symbol must meet performance standards set by the tire industry.

Basically, there is no such thing as an all season tire per se.

Summer tires are vastly inferior to winter tires on bare pavement when ambient temperatures drop below 7C. All the tire manufacturers say so. They have the data to prove it.

All season tire performance on bare roads compares to that of summer tires in that there will be more difference between good brands and cheap brands than between summer tires and all season tires. Nevertheless, Michelin Pilot A/S + will outperform Michelin Pilot Supersports on cold pavement. Period. That's why Michelin makes both tires.

You can think what you like but ultra high performance summer tires are absolutely useless in winter.

Michelin Primacy HP are just useless tires period, for anyone who drives hard. Useless in all four seasons.

[dsgerbc]

So no link with a test then, thought so.

Summer tires are vastly inferior to winter tires on bare pavement when ambient temperatures drop below 7C

That's a fantasy with zero proof. Even race tires don't have "glass transition" temperature that high, and most EP summer tires likely have that temp well below freezing. Even freaking A/S tires will brake 60-0 at least a car length sooner. It might've been true if there were a tire with 'winter' compound with exactly the same tread design as a summer tire, but there isn't.

Believe marketing all you want.

Anyone reading this - look at my links and judge for yourself. Braking distances and lateral Gs are right there. And please brake early and keep a somewhat larger distance when drying on the dry road on your winter tires. The driver ahead of you on A/S tires is likely to stop better than you in the event of a panic stop.

Another thing to keep in mind: Winter tires employ various amounts of hydrofilic compounds to get some traction on ice/snow. Summer tires have compounds that are hydrophobic. A/S tires usually have a touch of hydrofilic too. So in the wet/damp, when it's a few degrees above freezing, one is still better off with decent summer tires (not OEM Michelins though, lol) or A/S tires, compared to winter rubber.

Basically, if there's no chance of ice or snow on the road, summer tires are the way to go.

[bkblitzed]

nope my tires have never lost grip unless i did it on purpose when they're cold.

[Suberman]

Originally Posted by dsgerbc

So no link with a test then, thought so.


That's a fantasy with zero proof. Even race tires don't have "glass transition" temperature that high, and most EP summer tires likely have that temp well below freezing. Even freaking A/S tires will brake 60-0 at least a car length sooner. It might've been true if there were a tire with 'winter' compound with exactly the same tread design as a summer tire, but there isn't.

Believe marketing all you want.

Anyone reading this - look at my links and judge for yourself. Braking distances and lateral Gs are right there. And please brake early and keep a somewhat larger distance when drying on the dry road on your winter tires. The driver ahead of you on A/S tires is likely to stop better than you in the event of a panic stop.

Another thing to keep in mind: Winter tires employ various amounts of hydrofilic compounds to get some traction on ice/snow. Summer tires have compounds that are hydrophobic. A/S tires usually have a touch of hydrofilic too. So in the wet/damp, when it's a few degrees above freezing, one is still better off with decent summer tires (not OEM Michelins though, lol) or A/S tires, compared to winter rubber.

Basically, if there's no chance of ice or snow on the road, summer tires are the way to go.

You're from Michigan? Right?

I'll just go from my personal experience then, if you don't mind?

[dem00n]

Originally Posted by dsgerbc

So no link with a test then, thought so.


That's a fantasy with zero proof. Even race tires don't have "glass transition" temperature that high, and most EP summer tires likely have that temp well below freezing. Even freaking A/S tires will brake 60-0 at least a car length sooner. It might've been true if there were a tire with 'winter' compound with exactly the same tread design as a summer tire, but there isn't.

Believe marketing all you want.

Anyone reading this - look at my links and judge for yourself. Braking distances and lateral Gs are right there. And please brake early and keep a somewhat larger distance when drying on the dry road on your winter tires. The driver ahead of you on A/S tires is likely to stop better than you in the event of a panic stop.

Another thing to keep in mind: Winter tires employ various amounts of hydrofilic compounds to get some traction on ice/snow. Summer tires have compounds that are hydrophobic. A/S tires usually have a touch of hydrofilic too. So in the wet/damp, when it's a few degrees above freezing, one is still better off with decent summer tires (not OEM Michelins though, lol) or A/S tires, compared to winter rubber.

Basically, if there's no chance of ice or snow on the road, summer tires are the way to go.

And if there is?

[dsgerbc]

Originally Posted by Suberman

You're from Michigan? Right?

I'll just go from my personal experience then, if you don't mind?

I've lived and driven in places much colder than Michigan or most of Ontario.

Originally Posted by dem00n

And if there is?

Then swap for winter tires. All I'm saying that it's stupid to swap to winter tires once it gets below 47F/8C, because you're giving up a crapload of dry grip for nothing. Give it up for something, and fully aware of trade-offs.