NNH

Normally I'm exactly the same, which is why yesterday was a bit of a surprise - I was trying to get into a narrowing gap, and even three quarters throttle at 3000rpm was enough to get a bit sideways.

djantlive

Always watch out when acceleration midturn on any sports car. It must be done gradually even in good weather. Rain, snow and cold weather are especially tricky.

hwk72

Folks, I originally come from Austria, so I know everything about winter tires and modern young winter tires (not older than 3 years otherwise the rubber gets too dry to grip) are great to drive in snow and on wet roads but believe me on dry roads no matter what temperature, summer tires always beat winter tires if they are warm (it's logic that it takes all tires longer to warm up when temperatures are low). Autobild, Germany's largests car magazine performs every year an extensive tire test and can always prove that the temperature fairy-tale is an invention of the tire industry.

Harold

LVDell

So living in Austria makes you an expert on tires? You do realize that the rubber compound of winter tires and summer tires are different thus allowing the tire to perform in temp conditions commensurate with the compound regardless of road condition? It's the compound not the label. The average consumer wouldn't understand what tire to buy if they were just labeled by compound so labeleling them winter/all-season/summer/etc allows them to buy the tire that best suits their conditions and those labels usually correspond to a temperature range.

BruceP

I think what he's saying is that summer tires are always better on dry pavement, regardless of temperature, as long as they're warmed up. I never thought that was true, but I'd love to see something in the way of proof. Would be cool if true.

Yeah, I didn't get the Austria thing either.

LVDell

Yeah, I got that as well but that is where his argument FAILS. There is just NO way to get summer tires up to temp in the winter (cold) on dry streets with city driving. A track is a whole 'nother ballgame.

Sharptt

Imagine how bad it could have been without PSM.

hwk72

Dell, coming from Austria enables to read more diversified articles as I've more than one language for my research.

Here's a current link to Autobild: http://www.autobild.de/test/reifen/a...tikel_id=12460

And here's the quote:
"Bei nasser und trockener Fahrbahn ist der Winterreifen mit seiner weicheren Gummimischung und den unzähligen Lamellen dem Sommerpneu klar unterlegen. Weniger Seitenführung, weniger Aquaplaningreserven und ein längerer Bremsweg verschlechtern seine Leistungsbilanz auch bei niedrigen Temperaturen. Daran gibt es kein Deuteln. Auch wenn sich das Märchen von der Temperaturgrenze bei sieben Grad Celsius hartnäckig hält."

And a free translation:
"On wet and dry roads winter tires are inferior to summer tires. This is due to their softer rubber compound and enless fins. Less cornering, less aquaplaning reserves and a longer stopping distance downgrade their rating even at lower temperatures. That's for sure, even as the fairy-tale of temperatures below 7 degree Celsius (44.6 degree Fahrenheit) is still around."

Harold

LVDell

I guess all that censorship in the USA keeps us from reading anything other than Road and Track.

You believe what you want and we will stick with published fact rather than magazine anectodal evidence. If you are serious about the performance of tires you really need to check out the data sheets published by the manufacturers for each compound. Until then, feel free to run your summer performance tires in the winter thinking that they will work better.

bet

Dell touched on the issue that seems to always be forgotten or glossed over in the discussions of summer tires use in colder conditions. The normal everyday in and around town driving does not warm the tire up sufficiently to let the rubber compounds work properly. This is especially true in damp conditions.

While it is true that you can drive summer tires in cold conditions (not snow, ice, rain, etc.) and never experience “problems” it does not mean when you need to stop, turn or accelerate in an emergency situation or the driver has became to confident and over-cooked an on ramp, that the tires are going to grip and perform the way they are suppose to. Daily driving on public streets is at such a threshold that the tires never heat up and are not performing properly, but the same reason why the tire has not achieved the proper operating temperature is also the reason that most of the time there is never an issue. It is the one time that you need to stop very quickly or turn or accelerate or hit a damp part of the road that you find out that the tires are not working the way they are suppose to. If this type of risk is acceptable to you then by all means drive your car on summer tires during the winter and realize the risk exist, but don’t try to rationalize the use (to yourself or others) based on the premise that the risk is not there because you haven’t experienced it before.

hwk72

Dell the data sheet from the tire manufacturers must prove your point. I'd surely fire these guys as CEO of the company if they would not support my winter tire sales, academically your prove is worthless - sorry.

However, the compound is a valid point but winter tires differ in a lot of other attributes from summer tires than the compound and a total of all attributes combined define the grip of a tire. Tire manufacturers usually do not publish data sheets of their tire tests. The only one was once Michelin. They tried to prove a shorter stopping distance of winter tires on dry roads at temperatures below 30 degree Fahrenheit; but guess what their measured distance was 25% above regular distances what proves that they tested it on slippery asphalt where winter tires really stop better.

OK, you don't believe in German "magazine anecdotal evidence" fair point; however they actually publish test results compared to tire manufacturers.

A solid source is the ADAC, the leading German automobile club. One of their tire experts says: "Theoretically the thermo-thesis is right, but the exact temperature when summer tires harden is not proven but it seams to be below freezing point".

Conclusion is: it depends where you live and under which conditions you drive your car. No doubt that a daily driver in IL is better off with winter tires but I don't see that a weekend driver in NC or VA risks anything with summer tires on dry winter roads.

LVDell

You just confimed what I have been saying. Maybe your comments were TOO general and mine weren't state specific. But suffice to say, that I have NO need for winter tires here in NC. I will use a hybrid tire with a great treadwear rating for my Cayenne. My other cars run summer max performance tires year round. They just don't see the road if it is too cold or especially adverse weather.

So, I guess we were really saying the same thing from the beginning?

Ray S

Harold, you'll have to excuse Dell's ignorance. He's just a silly American (from down south no less) and does not know any better.

Most American's aren't aware that due to our war effort in Iraq all winter tire test data is censored by the Government. As you know Iraq has a very warm and dry climate. As such the US Military requires a ton of summer tires to outfit the fleet of Humvee's. They (US Government) censor tire test information so the US population will switch to winter tires and thus reduce the overall demand for summer rubber.

Thankfully, your extensive language skills have uncovered this viscous plot.

In all seriousness, I recently drove a Cayman loaner for 2 weeks in December. Our weather in Chicago during that timeframe was mostly very cold, but dry. My loaner was equiped with Michelin Pilot Sports and let me tell you they were lousy in the cold (dry) weather. They never got up to temperature and the grip was awful.

Toward the end of my time with the Cayman we got some snow in Chicago. The car was downright scary in the snow on these tires. I was very happy to get the my 996 back (with Blizzaks).

I just wish I was smart enough to read "Canadian", as I'm sure our neighbor to the North might have some interesting literature on the subject!! jk

hwk72

I agree Dell, we are saying the same thing, you in English and I in DEnglish (=German-English) - sorry for the confusion

This fall the "thermo-thesis" was a big deal in German media, so I wanted to share what the guys think that built our cars.

BTW I do also drive my X3 with hybrid tires on wet or rarely snowy VA winter roads but on dry days year around, I enjoy my 911 with summer tires (usually not in city traffic anyhow).

roberga

I do that most cool wet mornings pulling out of my driveway. Even more with the light weight flywheel. I only do it with nobody around to see. It is a lot of fun to see how far I can hold it with the throttle.