Has anyone noticed if their tires get flat spotted when cold. I have run 225/45 series tires for the last 8 years and never had that happen before. The outside temp dropped to about 35 degrees and upon pulling away from the curb the tires had a definite whump...whump...whump....whump. It went away after a few hundread feet but it was disconcerting to feel it.

 

yup, same for me

 

All I have noticed is the lousy traction.. It's lethal without traction control if the tires are cold!

 

All high performance summer tires will do that to some extent - it's because the rubber compound undergoes essentially a phase change when temperatures get near freezing, and the tread compound becomes much harder and less pliable. Along with 'flat-spotting", it also means that they will have FAR less grip than they do at warmer temperatures. This is another situation where winter tires are beneficial - at cold temperatures on dry pavement, a winter tire will have more grip than a performance summer tire.

That's for accelerating - have you tried braking or cornering yet? ABS and DSC, like traction control, can only manage to the limits of the tires, which are far lower as you've found. That becomes a real issue if you need to brake suddenly and find that it takes much longer to slow or stop, almost as if you're on ice (can you say "rear-end the SUV in front of you?") Many people think if they don't drive in snow they'll be OK with their performance summer tires (or even think they can get by if there's only a little bit of snow), but many of us have argued against this idea for months. Now there are many posts, like yours, that prove that performance summer tires are useless in snow and in fact on cold dry pavement, and there are also lots of posts attesting that with winter tires the RX-8 does very well in cold or snow.

Regards,
Gordon

 

I cringe to hear you NorthEasterners driving your 8 on salted roads.

 

Yes, I cringed as well, but the car has to go where I need it to go, and that means through the snowy salty streets. Salt can be mitigated to some extent by properly washing the car. However, the most devastating thing that I have ever witnessed is the effects of extreme humidity differentials to a car. The temperature drops and the entire car, seats, carpets, everything is soaked as if a torential down pour had hit it. That can devastate a car.

 

... then the next morning, your beautiful RX-8 is so far inside of a block of ice, that it looks like a David Blain stunt.

 

Who is David Blain?

 

My baby is sitting in the garage waiting for the nice sunny day to take it for a spin. It's hell going into the garage and seeing a clean red car just waiting to be driven.

 

I might say that David Blaine is the most amazing magician since Houdini, but I won't because he blows away Houdini.

Ice stunt:

http://www.magicdirectory.com/blaine...nintime2.shtml

More:

http://www.davidblaine.cjb.net/

 

Wow. I was just gonna say, "Some magician guy." lol

 

The REO4O's are an extremely soft compound, treadwear around 140 so thatmigh explain the "cold spotting". They were the OEM tires on my 2000 S4 and replaced them with Pole Position S03's. They S03's are a much better tire with a stiffer sidewall, some what firmer ride, superior steering feedback and superior cornering.

 

I haven't noticed flat spots, but when I start my engine on cold mornings, the tire pressure warning light comes , but goes off after driving a few miles. Anyone else?

 

Check your pressures. I suspect that there is a difference between tires. Check out the thread below.

https://www.rx8club.com/showthread.p...455#post195455

 

My pressure warning went off when the weather got cold and one tire was in the 28 lb. range. Filled them all to 33psi and no more warnings.