gregg2gs

Is it true that the RFTs, Bridgestone Potenzas, may loose traction on a dry road becuase of below freezing temps??

JStraw

I am certainly no expert, but here's my $.02...

First of all it's got nothing to do with RFT. They do make RFT Winter tires (I have a set), which provide excellent traction in winter.

Secondly, the rubber compounds for summer vs winter tires are substantially different. Winter rubber compound are softer and remain soft in below freezing conditions. Summer tires are designed (compound and tread design) for traction and handling in dry and slightly wet conditions. These compounds become "plastic" when exposed to freezing temps, therby loosing traction.

Hope this helps.

gregg2gs

Yes. Helpful.

Scal of 1-10 (10 worst)...how dangerous to drive with summer run flats in below freezing?

doug_999

JStraw's advice is right on. Your second question is harder to answer. The fact is that it is not that dangerous to drive with summer tires (forget about the runflats, they just don't make a difference here*) below freezing. HOWEVER, any moisture on the road and you are in deep, deep trouble.

I'll never forget a friend who worked only a mile from home and drove home in a snowstorm with his summers on. He called me crying. Took him over an hour and could not get up over the lip on his driveway (1"). Or my neighbor who refused to put winter tires on his 545 and almost got stuck on railroad tracks once.

In any event, keeping summer tires on in the winter is pretty dangerous. You never know when it will rain/snow/sleet.

*Run-flats actually tend to do worse than non-run-flats in the rain. I forget the reason for this.

Bawa

On a scale of 1-10 (10 being worse) I would give it a 12. I can tell you first hand that its next to impossible to drive in wet/snowy conditions with summer run-flats. I bought my CPO 545i last Jan and got caught in a snow-storm on the way to getting winter tires installs - it was the worst drive of my life!

unknown

gregg, you can drive in freezing winter with summer tires as long as the roads are not icy and snowy. just dont push it hard like it was summer. again, never drive even a hint of snow or ice

studavis

Gregg,

I cannot find a single credible source that indicates RFT?s perform worse in cold weather compared to standard tires. I would tend to doubt any assertion that the RFT's suffer traction loss due to cold weather on DRY roads. The compounds in winter tires, are formulated for snow and ice, not for colder ambient weather. The leader in this class is the Blizzak, which if memory serves was one of the first new generation snow tires, introduced in the early 90's. The tire has millions of little holes in it to act as little suction cups on ice, and the tread compound is supposed to help with snow traction. I ran a set of these once on a Taurus SHO, and thought they were great. Here is a link to a forum of people on the Edmunds site that argue forever on how much they love/hate the RFTs on BMWs.

http://townhall-talk.edmunds.com/direct/view/.efceb01/0

Rudy

This is not a run-flat/non run-flat issue, it's a summer tire/winter tire issue.

Summer tires lose their softness in the cold (whether they're run-flat or not) and traction does suffer, even on dry roads. Clearly, this loss of traction on dry roads may not be as severe as the much more significant traction loss on a snow covered or icy road but traction does suffer. I don't need any more credible source than my own car's behavior. A couple of days ago, when it was in the mid to upper 30s, my rear tires wanted to break loose during acceleration but just today, with the temps back up in the 50s and 60s, the tires gripped much better (on the same dry roads...)

JStraw

I agree with Rudy.

You will greatly reduce traction and increase stopping distance if you drive with summers in below freezing. It could be dangerous to do so. I don't think I would want to try it.

I got caught last year with summer tires and the first snow of about 2-3 inches. I could not get out of our cul-de-sac, and had to call my neighbors to push me back to the driveway. Luckly, the snow melted ater a couple of days, and I was able to drive to the dealer to get my winters put on.

gregg2gs

Thanks everyone. Very helpful. I will keep it in the garage and use my jeep. Thanks!

Darn I'm gonna miss her. What temp do you think it starts getting dicey?