Originally posted by Mystang:
The guy behind the counter said it was because the overall hight of my tires is shorter than the factory spec and that was causing my tires to sit at an uneven level thus the insides will wear quicker on the inside and cause tread separation.


I'm not sure, but I think you're saying "the guy behind the counter" was telling you your camber was changed by using a tire with a different overall diameter than the OEM (stock) tire. Uhhh... no.

All else being equal, installing tires with a different overall diameter changes the ride height of the car and the number of revolutions per mile (which in turn affects the accuracy of the speedometer/odometer). The camber, however, is not affected. The springs compress as much as is needed to support the sprung weight of the car, and that doesn't change just by changing tires.

Installing lowering springs, OTOH, will certainly change your camber ("tilt" of the wheels as viewed from the front) unless you have an equal-length dual control arm setup, which we most assuredly don't. With a single control arm, the longer the arm, the less camber is affected by lowering springs. At any rate, changing the neutral ride height of your car will create more negative camber and will accelerate the wear of the inboard tread shoulder to some degree. Get "before" and "after" alignment measurements to quantify the change in camber.

As was pointed out, 50,000 miles on a set of tires isn't bad, especially if the car was flogged at all. As a tire nears the end of its useful life, the slightest misalignment issue will become readily apparent, and eventually the tire will simply fall apart.

As regards the expected life of a tire, look at the sidewall of the tire for the "Treadwear" rating (a 3-digit number with a couple of letters behind it, such as "300 A A"). You can use this number to compare different tires as to their expected rate of tread wear (a 400-rated tire can be expected to last twice as long as a 200-rated tire).

HTH... Sorry for the dissertation, but I'm sick at home today, and the Web is preserving my sanity... sort of...

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