Good morning.

I have a 99 C5 and am about to put the second set of tires on it. Ive order the Kumho Run Flats. I have two questions maybe someone can help me with. First, I dont seem to get any better that 20 to 25K out of a set of run flats, is that normal. Second, my passengers side rear tire is almost bald while the other rear tire has considerable tread left on it and both fronts have a really good amount of tread left. Im curious as to why the passenger rear only wore out so bad. Another question, can I leave the fronts on which have a lot of tread left and mix them (Firestone Firehawks) with new Kumhos on the back.

Thanks
Bluslvr in Bowleys Quarters
Bluslvr@comcast.net

 

Check the rear passenger side suspension for worn,broken or loose parts and then get a good four wheel alignment.

 

http://forums.corvetteforum.com/show....php?t=1536778

I and many others consistently get 40K plus ( in my case K ) out of a set of Good year run flats.. tire pressure and alignment are the biggest factors..

Many here subscribe to 30 psi cold... which is ok... but 30 psi HOT is much much better. In climates that see 30 degree from cold to hot in 24 hots.. setting tire pressure cold...leads to + 4 or 5 psi when hot.. tires at 35 psi will wear prematurely, cause a center high condition, reduce lateral foot print. 45,000 miles can be done... and still have fun with the car... I had 4/32 left on the fronts and 3/32 left on the rears when I hit 43,000 miles. Tire wear was even.

Kumo's will not wear as well as the Firestone's.

People may tell you you can do it, even the tire store... they will say anything to make a sale... many people just think it is OK because they are the same type of tire... many people have mixed tires all their life and think run flats are like regular tires. Be careful who you listen to here..many will encourage you to do what they have done...it doesn't make it right or safe. It just gives them peace of mind to encourage other to do what they have done. Be it right or wrong.

Run flat technology varies greatly from one manufacturer to another... the side wall design is very different... I would Not mix two different manufacturer's run flats, handling will suffer, and safety could be an issue when in a panic condition ( like swerving to avoid a deer ) active handling will not correct for different side wall deflection..

Hope this helps
Bill aka ET

There is no problem with a non run flat tire mix... But Run flats have very focused sidewall design... and they are not the same...

--------------------------------------------------------------------------------
Last edited by Evil-Twin : Today at 05:17 PM.

 

on getting an alignment done; I've never had any problems with tire wear differing from side to side.

Also, as Bill mentions, it's best to stay with the same brand/types of run flats. Obviously you can mix them as long as you are reasonable in driving, but they will act differently.

For that matter, even if you replaced the rear tires with new Firestone RFs they're going to act differently, just because the front tires are older and harder.

HTH, and have a good one,
Mike

 

Is the passenger rear worn evenly across, or only bald on one side.

Even across could be air pressure, one side would be alignment.

 

I know that the goodyear runflats don't last much longer that that on average. I got 22000 and didn't abuse them. Get a four wheel alignment for the uneven wear.

 

Not too sure 22K is average.... most of my friends who subscribe to my Hot tire pressure theories, see on average between 40 and 45K... we are talking Goodyear runflats here too.

I have 22K on my second set of tires... Michelin Pilot sports... and they look like the day I bought them...
if 22K was average then these would or should be down to the wear bars2/32.... and they are at 8/32 front 7/32 rear.

 

30 psi hot is about 27/28 psi cold?

The tires last, and it's definitely a better ride as well, but what does it do to the wheels when you hit a pothole like we have in NYC here?