The weather is getting cold and my Magnum has a vibration when I first start out kind of like the tires are flat spotted untill they warm up a little. They are Continental run flats. Anyone else experience this? Ben.

 

Yes. I think they all do that. My friend also bought an RT and his does it the same thing as does mine. We've had ours since last May and they do it all year long, all temps. I believe, but don't quote me on this, that it has something to do with the sealant in the self sealing tires. It stops in about 3-4 minutes of movement.
Don't worry about that, its nothing.

 

My Contis don't do this. Wish I could say you're not alone.

 

What do you mean by cold weather? Give us a temperature so we have an accurate idea. It is common for tires to do that when it is cold, say below 35 degrees.

I have the self sealing tires also (Continentals) but here in Florida, I have no problem. Is your car garaged or does it sit outside, mine is always in the garage overnight.

Bob

 

I had that with my self-sealing tires for the first month or so that I owned my RT. I don't seem to be experiencing it any more. And FYI--I bought the car in late July, which was ~110 degrees here in Phoenix, so it maybe has to do with extreme temperatures? Very hot and very cold?

 

Had this problem for the 1st time today. Below 32 in Charlotte and for the first mile there was flat spots on the tires. I currently have 34 lbs of air in the tires.

 

Along those lines, when I first checked my tires after about 1k miles (shame on me!), they were at 27psi. I inflated them up to the recommended 30psi, and it did get quite a lot better. MyRT, try lowering your pressure to 30psi and see what kind of effect it has, if any, and report back. That would be a good experiment. Maybe these self-sealing Contis are finicky when it comes to pressure and temperature.

 

The temperature was under 30. I'll check the tire pressure. I have over 7000 miles on the Magnum. The car is garaged every night.