Problem with 19'' Michelin PSS

[unicenter]

Hi.

Today i put new tires 225/35/19 & 255/30/19 Pilot Super Sport at my car.
When i went for a ride with the new tyres i notice that the car is very nervous at driving and very unstable even at straight line also at corners.
It is so bad that you cann't drive fast for any reason.
It is 35i with m suspension and 313 performance wheels.
Does anyone her know why???
Need your help.

Thanks

[CedarZ4]

Did you get them balanced when you got the tires mounted or were the old ones just taken off and new ones mounted back on and the shop called it a day?

I don't personally have PSS, but I did go from RFT to non-RFT, and before they were balanced the ride was very wobbly for sure.

Another possibility (but related to balance as well) is that while mounting, they could have knocked off a few weights on accident... Definitely check that first. And if the wheels won't balance, then I will look into a manufacture defect tire.

[E89Tardis]

Did they possibly talk you into an alignment and then mess it up ?

[VailM3]

sounds like balance and alignment issues.

[jparnes1]

It's NOT the tires.

[unicenter]

The balance is ok.
Also the pressure is 36 front 45 rear.
How you are sure that is not the tyres???

[mbetoni]

Originally Posted by unicenter

How you are sure that is not the tyres???

I think what JP meant is that many of the folks here run PSSs with no problems whatsoever, so anecdotally, it's probably not the tires.

As others have said:

Balanced properly? Aligned? Beyond that, dumb place to look, but I've seen dumb things before: tires are unidirectional and staggered, are they all on the correct side/facing the right way? If all that checks out might be time to start looking for some suspension gremlins (bushings, tie rods, etc).

[jparnes1]

A long time ago I had a front set of no frills tires mounted and the car developed the shimmies at high speeds. After alignments, etc (with no success), I swapped the fronts and the rears and the shimmies went away. Bad tire(s). It's possible, but I doubt this would be the case with Michelin. It's' very likely something mechanical.

[CedarZ4]

Originally Posted by jparnes1

A long time ago I had a front set of no frills tires mounted and the car developed the shimmies at high speeds. After alignments, etc (with no success), I swapped the fronts and the rears and the shimmies went away. Bad tire(s). It's possible, but I doubt this would be the case with Michelin. It's' very likely something mechanical.

I agree it is most likely mechanical, but just for argument's sake... When I was looking at UHP A/S tires, I came upon the Michelin Pilot Sport AS and really liked it. Upon further research, looks like it had a lot of quality issues with the tire in various batches - namely pre-mature chunking. I know it's a difference tire and the PSS is such a high-demended tire it should be fine, but not something I would rule out completely. More importantly, who knows if the quality control is the same in Greece compared to the US. But anyway, off-topic.

OP, like every said. Check balancing and alignment. Making sure the tires are mounted correctly (outside is outside) and if all else fails, would then look into the tires themselves.