About 5k miles ago I purchase a set of stock 235 PZero Nero Super Hi-Perf tires from the Tire Rack. Since that time I have spent over $150 and 6 wheel balancings (from 3 different shops) trying to get the rear tires from going out of balance above 70 mph. The only reason I replaced the original RSA'* is that they were crap in snow (although fantastic in wet and dry!).

The RSA'* I removed were very smooth from 1-85mph so I know it is not a problem with the suspension or anything else in the SSEi for that matter. The last place I took it to used some high-falootin' Hunter Road "Something or Other" balancer and a special hub adapter that allowed them to balance the tires (they say) much better. No luck after 2 tries. After the 2nd try they said the 2 rear tires had manufacturing flat spots (I could feel nothing unusual and was very doubtful about their prognosis). Anyway the Tire Rack replaced both rears with new tires (no charge). That remount cost me another $50!!! Guess what....NO CHANGE. The ride is very smooth right up to 70mph then I get that "seat of the pants" vibration. I'm stumped and running out of money. What gives? This whole thing has taken the fun out of driving her. I have learned my lession about buying tires on line. At least if I had bought them from a dealer I would be dollars ahead. As it is I can't keep blaming the Tire Rack and exchanging tires with them. That is certainly not fair. PS- dry and wet handling with the PZeros is everything and more I've heard about these otherwise fantastic tires.

there is a possibility of a wheel being out of round aswell.. i would try rotating the tires and seeing if the vibration moves up to the steering wheel

could warped rotors be a possibilty?

Could be a broken belt etc.

You can balance some tires all day long...but it'* not the balance...it could be an internal issue that will only show when it'* on the car.

Bent wheel or wheel hub?

I have those same tires and size. Smooth like butter up to speeds I can't talk about here.

Thanks for the adivice guys, but remember.... before I removed the old tires and installed the new ones the rear-end was smooth up to 85 or so. Based on this I don't know how I could have a bad part back there.

Any tire guys out there??????????????

Are your valve stems lined up with the red dots on the sidewalls?

wikoff,

Red dots on the sidewalls?

Mine came with red dots on the sidewalls. They are spun for balance at the factory to find the point most advantageous to place the valve stem to reduce the need for wheel wieghts.

I suppose not all get them, depending on who orders them...

I have a 2000 SE. My old company car. Came with Firestone Affinity. The affinity tires seemed OK but wore out at about 25k.Worked great till I rotated them. Company would only rotate every 10k and would not allow alignments, as cars were turned over every 36mos/36,000. At 25k, Firestone put on a set of FT70C'*. They wore uneven due to no alignment.

When I bought the car I had a set of V rated Firestones put on. I could not get those tires balanced period. First had two alignments, balances, etc.

Took them from the Firestone dealer to another dealer. Paid $125 to force road balance. No luck. Finally, had the tires taken off and put on Bridgestone Turanza el200? These are T rated tires. Force road balanced. The car is about 95% back to where it used to be. Very nice tires.

2nd dealer, who has extensive experience with Lexus and high end cars was convinced that the tires were IMPROPERLY STORED!! He told me that if tires are stored on their side vs. being vertical, it definitely effects the belts. He also told me that he thought the rubber compound may have been too stiff for my suspension.

Now maybe everyone thinks he'* crazy, but he called Firestone and spoke with them re: his findings. Firestone reimbursed me for the new Bridgestones, mounting, balancing alignment and road hazard warranty. My tires were a year old, and I was trying to remedy this since they were new. They were great.

Sounds like you are having the same problem as I was, and another poster may have hit it on the head re: the belts. Firestone picked up my old set of tires and I know they were sent for examination. But they told the 2nd dealer that their findings are for future use and they would not discuss nor reveal what they found, if anything.

Being you got these mail order, I would call and insist on another set not from the same group. The dot or small circle referred to by another poster, in my case it is yellow/gold, does in fact line up with the stem.