Tire change, squirelly ride
 

Hi All, could really use some help. Just installed Michelin Pilot Sport A/S Plus ZP on the rear of my 2006 C-6 Coup, basic coupe, P285R35ZR19. I like the fact that they are quieter and a better ride than the stock GoodYear run flats that came with the car. The fronts are still the stock Goodyear P245/40ZR18 run flats. All tires set to 30psi per spec. The problem now arises that the car feels squirelly on the expressway, even at moderate speed of 65-75, it wants to wander and doesn't feel as secure as when all tires were the Goodyear ones. I hate to go back to the GoodYear run flats, but I am at a loss to figure out how to correct the unsafe feel of the car., Any observations or suggestions would be greatly appreciated. Thanks

i am looking forward to the reponses as i am at the same crossroads. going with the same michelins on rear and keeping oem on front .

spice

Shouldn't mix tires!! Put a set of the Michelins on the front and then take it to a good alignment shop and get it aligned......

Mark :flag: :flag:

That's the exact reason that I changed all four tires when I went with the Michelins. I would have been in the opposite boat, though, as I would have been replacing the fronts with Michelins.

I was concerned that the handling would be bad because the Goodyears are extremely stiff, while the Michelins have a softer sidewall.

Really bad idea. I'm surprised the tire store allowed this. Really bad mix of tire types...oh boy...

I just replaced my OEM GY's with a full set of Michelin PS A/S ZP's. It's the way to go. Tracks true. No squirrels.

:iagree: Probably will be even worse on wet streets, please be careful.

new tires
 

Another reason could be the oils that the new tires have on them. You need quite a few miles before the rubber perfoms the way it is suppose to.

As it was already said, you should NEVER mix tires, and even less leaving OLD FRONT ones in place man. And second, you need to break them in. It takes at least 100 miles to get rid of their greasy film from manufacturing. And finally, which tires did you have? If you had summer tires, the A/Ss are ultra-high performance all-season, which probably is the best compromise between performance and cold weather capability, BUT they obviously won't stick like a summer tire in warm conditions. Now go and buy the front tires before you have an accident man :smash:. Good luck.

Big mistake. Buy new Michelin Pilot Sport A/S ZP's for the front before you end up in the ditch. Or worse.

When I got new rubber on the Peterbilt, the 8 driver wheels, the truck was hard to keep in the lane on twisty 55mph roads. At least for a few thousand miles.

Change out the fronts and get a proper alinement. I like the Pfadt Street specs.

I went thru this too, you are gonna have to change the fronts to match the rears and all will be fine.

I put 4 of those Michelins on my '08 two weeks ago. It tracks straight and true. I'm very happy with them. Don't fool around with mixing tires; put the Michelins on the front.

as said above, two new fronts. or if you like the "savings" by keeping the fronts, two new rears that are the same brand and type as the fronts. under adverse conditions, you could have found yourself in a world of trouble. lucky it didn't happen.:thumbs:

No offense to any of the posters here, but I've run all sorts of combinations on my 2 c5's and my C6. Never had an issue and drive the car pretty hard whenever I can. Currently have the Pilot ZP's on the front and Nitto R compunds on the back. It is awesome.

I would have it aligned before spending more money on tires.

Just my .02.

yeah mixing tires is not that big of a deal. the "wondering" is b/c the tires are new and a little greasy. Give them a few miles, or maybe one quick burn out and you'll be fine.

Why would 2 different tires front to back have anything todo with squirrely behavior in a strait line? lol

yes it does make a difference. I had bfg kdw2's on my car and switched to nitto invo's (345-30-19) for GS wheels. I left the bfg's on the front with nitto's on the rear, got on the highway and it felt like I had 2 flat tires on the rear. The car was all over the place. It was so bad at 80 the car would change lanes by its self. So, I pm wolfdogs and he said the nitto's have a thinner sidewall than the bfg's. I went down and got nitto's on the front and problem solved. Except my newly black painted GS wheels shredded the paint off the second the tire came off. So discount tires had my wheels powdercoated

I had Invos on the rear and GYs on the front of my 06Z for about two weeks of DDing while waiting for the fronts to come in. The handling was very quirky. The car was squirrely on most roads at normal cruise and it was was quite a handful under power. Installing Invos on the front fixed the problem.

Moral of the story: Mixing tires of different types can cause trouble - especially runflat vs. normals.

Went from Goodyear Supercars to PS2ZP's full set, even though the rears still had some mileage left. I would never mix makes like you did. The results are what you got. Now go finish the job with the other 2 Michelins and you will be fine.

I went from the GY supercars to the Michelin Pilot Sport A/S Plus ZP. The Michelin's handle very well for about 85-90% driving. I have had no strange behavior out of the tires, but I changed all 4 at the same time. I agree with the others and would put some Michelin's up front to complete the set.

Sometimes mixing tires isn't a big deal and sometimes it's very hazardous. The Mich vs. the GY are very different in sidewall stiffness, so a problem resulting is no real surprise. If you really want to try to save your current purchase, you might play with air pressure. loose some psi in the GY or gain some psi in the Mich...or both. Good luck....you may need it.