QuestionI have a 2002 Boxster S, fow which I just purchased a new set of Pirelli PNero-Nero M&S tires. The original Yoko AVS Sports wore out in 12000 miles. The new tires are the exact sizes of the old ones they replaced.
As soon as I started driving on the new tires I felt a vibration on the steering wheel once I went above 65 mph or so. I brought the car back for re-balancing and after 2 hours of fiddling with it they told me they could not do anything more without replacing the front tires. They felt that the front tires were out of round. Does this sound reasonable?
The Porsche dealer told me I needed "high performance balancing". No tire services I spoke to, including national chains and boutique shops, knew what I was talking about.
Thanks!
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Follow-Up
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Wally, thanks so much for the nice comments. I appreciate that.
As for Porsches either getting or needing on-car balancing...I doubt both statements apply to the vast majority of these fine cars. I think you'll agree that most new tires put on Porsches would be mounted by the big national chains...and while they may be able to do on-car balancing, it's usually not done because it takes more effort. And I love Porsches but the notion that their suspension system is so delicate and fine-tuned it requires special balancing is foo-foo. Now if Ferrari said it there may be something to it.
Just one man's opinion. Thanks again
Dave
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Hi Wally,
I think you're asking whether a description of "out of round" tires was reasonable...and whether I know what a high performance balance is.
I'll start with the high performance balance question. It's no surprise that the tire retailers you contacted couldn't define this phrase. The dealer obviously knows what he's thinking when he uses the term, but the words are so generic that even if a tire retailer said sure...we do high performance balancing...I'd bet it wouldn't be the same process as the dealer was referring to. They'd both have "high performance balancing services", but they wouldn't necessarily be the same.
The average national retailer does dynamic balancing, which is much better than static balancing of yesteryear. Dynamic balancing simply means the new tire with wheel is spun on a balancing machine and the machine gives the operator data on how much weight to add and where (somewhere around the circumference of the wheel) to add it. The balancing process attempts to even out the out-of-roundness of new tires (meaning more weight is located at a certain point on the tire than it should be). Balancing also accounts for the fact that wheels too are often out-of-balance (meaning the wheel's weight is not always distributed equally around the wheel.
A MORE high performance balance than dynamic balancing would be to balance the tire and wheel assembly on the car, on the hub where the new tire willbe used. This attempts to balance all that I've talked about AND the car's hub and brake rotor.
A MORE high performance balance than this would be to shave a small amount of new tread from the tire thereby lowering any highspots, making the out-of-round tire much less so. Then the tire wnd wheel combo could be mounted and balanced on the car as noted in the previous paragraph.
There are probably even more sophisticated techniques used for racing, but the ones I've mentioned are used in car repair/tire retailers around the country.
As for whether a description of "out of round" tires is reasonable...the answer is that such a description is reasonable...BUT what's not reasonable is for the retailer to say, in effect, the tires we sold you are out-of-round and should be replaced...but we're not going to do it. Now that's unreasonable. Why won't they replace the "defective" tires for you? I'm sure I'm missing something.
Dave
