spagolli94

My summer tires vibrate on the highway for the first few minutes, then they smooth out, eventually becoming perfectly smooth. I'm assuming this is from flat spotting when the car sits. Funny thing is, the car doesn't need to sit for very long. Just a couple hours seems to do it. Is this normal for summer tires?

India Whiskey Charlie

A couple hours is too short of a time to cause flat spotting. What kind of tires do you have? When I had the OEM P-Zero's on, they did that, but it was after 5 days of not driving. The current Bridgestone's don't seen to exhibit any flat spotting in as much as 7 days of not driving. I'd say make sure you have the correct tire pressures and just don't worry about it.

Reggie

I agree here -
Check your pressures.
Also rotate your tires and have them rebalanced - could be a slight off centering of the wheels and/or tires.

RS4@LAST

Mine does the same (not all the time, just some times). I've had this issue with a huge variety of tyres over the years. With my current 'crap' Toyo's, its worse if i hit a few corners hard when they are dead cold. Like you said, goes away after a few minutes.

spagolli94

I have the Hankook Ventus V12. I don't think I have any issues with balancing or centering. If I did, the problem would be more permanent in nature and wouldn't disappear after a few miles. I've had this happen with other tires (on other cars) before, but only after the car sat over night. I'm currently running 38F 35R, but might try bumping those pressures up a bit.

The Hanooks feel really soft (incredibly smooth and quiet over poor road surfaces). Maybe that has something to do with it?

uberwgn

Spag, you might also try locating a shop with the Hunter RoadForce machine. That can quickly ID problematic tires faster than anything else if you can't find another solution.

spagolli94

Yeah, I've had road force balance done before. The vibration is very minor and only lasts a couple miles at most, so I really don't think it's a balancing issue. In fact, after a couple miles, the car is as smooth as glass. Therefore I'm hesitant to fix it if it's not broken. Road Force balances can be tricky. Many shops have them, but they are either not calibrated correctly or the techs don't know how to use them properly.

I'm 99.9% sure it's temporary flat spotting on soft summer tires. Otherwise the issue would not go away after the tires come up to temp. Does anyone else have the Hankook V12's on this car? What PSI are you running? PSI is tricky in the spring, due to large temp swings. I've heard that every 10 degrees in ambient temp results in a +/- 1 PSI change in tire pressure.

uberwgn

I used to get flat spotting on my previous car. It only happened when it was hot and the car had been sitting for an hour or so. I'd never experience it if the car had been sitting for a few days. I learned to ignore it