One more summer tire comment/question
01-07-2008, 07:35 PM
#16
Drifting
When it is said that tire X is designed to work about Y degress C, do they mean that Y is the temperature of the environment, or the temperature of the tire? Spirited driving on a freezing day will make a tire hot to touch.
01-07-2008, 08:39 PM
#18
Drifting
If so, then this has big implications for our discussion.
I'm no tire engineer, but I do recall the Top Gear episode where Richard Hammond must drive a Formula 1, and had problems because he wasn't driving fast enough and the tires cooled, causing him to lose traction.
I'm no tire engineer, but I do recall the Top Gear episode where Richard Hammond must drive a Formula 1, and had problems because he wasn't driving fast enough and the tires cooled, causing him to lose traction.
01-07-2008, 10:34 PM
#19
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I know that my OEM summer tires would suck in the snow - got that point well driven in from all the previous posts on the topic. And looking at the on-line tire specs for my SportContact2 Continentals, 44 degrees is the temperature below which the tires are not recommended (in reading the manual or the tire ads, it just says "near freezing temperatures." I was a bit surprised that 44 degrees counted as "near freezing.")
So taking that all in, my question is whether or not my summer tires will give me noticeably degraded performance at temperatures, say, 45 - 50 degrees. A lot of winter days are in that range here, and I'd like to drive the car (c2 cab). The car only sees dry roads and I wouldn't use it in any kind of wet/snow pack situation even at >45 degrees. Is there much of a performance curve, so that 50 degrees is worse than 60 degrees and so on until at 44 degrees and below they simply become unsafe even on dry roads?
For those who use their summer tires in the way I've described, do you need to drive any more gently?
Thanks for sharing your experience.
Kevin
So taking that all in, my question is whether or not my summer tires will give me noticeably degraded performance at temperatures, say, 45 - 50 degrees. A lot of winter days are in that range here, and I'd like to drive the car (c2 cab). The car only sees dry roads and I wouldn't use it in any kind of wet/snow pack situation even at >45 degrees. Is there much of a performance curve, so that 50 degrees is worse than 60 degrees and so on until at 44 degrees and below they simply become unsafe even on dry roads?
For those who use their summer tires in the way I've described, do you need to drive any more gently?
Thanks for sharing your experience.
Kevin
01-08-2008, 08:57 AM
#20
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Sorry for not reading through all the replies, but here's my experience.
I've been driving on PS2s since they were released several years ago. First on my M3 and now on my 997S. I use them as my early spring / rain track tires. Early spring here means the day starts at Lime Rock at about 26-28 degrees and warms up to about 35-40. That means the track is cold and the tires are cold. The PS2 is simply amazing in the cold. At 30 degrees or under, yes, I have to pull back a little, but I still have great traction (cornering and braking). From 30 on up, they are pretty much "normal". With my old tires (Pilot Sport), they were a mess when it was cold. So, not sure how this applies to other brands of tires, just that the newest compounds are pretty good in the cold...
I've been driving on PS2s since they were released several years ago. First on my M3 and now on my 997S. I use them as my early spring / rain track tires. Early spring here means the day starts at Lime Rock at about 26-28 degrees and warms up to about 35-40. That means the track is cold and the tires are cold. The PS2 is simply amazing in the cold. At 30 degrees or under, yes, I have to pull back a little, but I still have great traction (cornering and braking). From 30 on up, they are pretty much "normal". With my old tires (Pilot Sport), they were a mess when it was cold. So, not sure how this applies to other brands of tires, just that the newest compounds are pretty good in the cold...
01-08-2008, 11:11 PM
#21
Instructor
Thread Starter
For what it's worth:
Most of the more authoritative data I've gotten from searching articles and the like since posting the question come from the various manufacturers. All seem consistent in saying that the "summer compounds begin to lose their elasticity and begin to harden when the temperature is below 7 degrees C" (44 degrees F).
The 44 degrees is consistently the number they cite and the word "begin" is consistent as well. So on dry pavement, I take this to mean that at temperatures above 44 degrees, the rubber doesn't display any diminished properties. If the tire temperature once you drive is always higher than the ambient temperature, well I guess that just gives me some margin of error.
Now I don't know if "not hardening" means that all the "stick" that summer tires have in July is there as well, but I'm not going to drive it hard enough on 45 degree dry winter days to find out.
Kevin
Most of the more authoritative data I've gotten from searching articles and the like since posting the question come from the various manufacturers. All seem consistent in saying that the "summer compounds begin to lose their elasticity and begin to harden when the temperature is below 7 degrees C" (44 degrees F).
The 44 degrees is consistently the number they cite and the word "begin" is consistent as well. So on dry pavement, I take this to mean that at temperatures above 44 degrees, the rubber doesn't display any diminished properties. If the tire temperature once you drive is always higher than the ambient temperature, well I guess that just gives me some margin of error.
Now I don't know if "not hardening" means that all the "stick" that summer tires have in July is there as well, but I'm not going to drive it hard enough on 45 degree dry winter days to find out.
Kevin
01-09-2008, 10:31 PM
#22
Instructor
This is a pretty interesting discussion. After reading I went to Michelin's site to look up the temperature rating for my PS2's and can't find it. I don't drive my car a lot during the winter, just on nice days when the temps will be in the 50's or higher with dry pavement. When I have I have not perceived any loss of grip, although I haven't driven really hard or fast and wait until the oil temp is up before pushing revs or turns (so the tires ought to be warmed up some too). So that seems pretty consistent with RonCt's point.
My club is starting (this month) to autocross year round instead of quitting in October. Our next event is Sunday when the high will be 53 but starting temps will probably be around 40. Man do I have the itch -but since I don't drive a lot in winter, and never had the opportunity to autocross at this time of year before, I have never considered another set of tires.
My concern is that on the first run, or two, of 3 on the autocross track (which is about a mile in length) the tires would be cold from sitting. The track is pretty narrow since it's set up on a law enforcement track and not on a big patch of asphalt. So there's not a whole lot of room for error...
My club is starting (this month) to autocross year round instead of quitting in October. Our next event is Sunday when the high will be 53 but starting temps will probably be around 40. Man do I have the itch -but since I don't drive a lot in winter, and never had the opportunity to autocross at this time of year before, I have never considered another set of tires.
My concern is that on the first run, or two, of 3 on the autocross track (which is about a mile in length) the tires would be cold from sitting. The track is pretty narrow since it's set up on a law enforcement track and not on a big patch of asphalt. So there's not a whole lot of room for error...
01-14-2008, 11:42 PM
#23
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Sorry for not reading through all the replies, but here's my experience.
I've been driving on PS2s since they were released several years ago. First on my M3 and now on my 997S. I use them as my early spring / rain track tires. Early spring here means the day starts at Lime Rock at about 26-28 degrees and warms up to about 35-40. That means the track is cold and the tires are cold. The PS2 is simply amazing in the cold. At 30 degrees or under, yes, I have to pull back a little, but I still have great traction (cornering and braking). From 30 on up, they are pretty much "normal". With my old tires (Pilot Sport), they were a mess when it was cold. So, not sure how this applies to other brands of tires, just that the newest compounds are pretty good in the cold...
I've been driving on PS2s since they were released several years ago. First on my M3 and now on my 997S. I use them as my early spring / rain track tires. Early spring here means the day starts at Lime Rock at about 26-28 degrees and warms up to about 35-40. That means the track is cold and the tires are cold. The PS2 is simply amazing in the cold. At 30 degrees or under, yes, I have to pull back a little, but I still have great traction (cornering and braking). From 30 on up, they are pretty much "normal". With my old tires (Pilot Sport), they were a mess when it was cold. So, not sure how this applies to other brands of tires, just that the newest compounds are pretty good in the cold...
