Wheel alignment issue? Odd tire wear.

[Boxxy]

From my username, many would know that I'm a current 986 owner, but I'm also a new member of the 996TT club(!)

The 996TT I'm getting has new but oddly worn rear tires. After less that 4000 mi, the rear tires are excessively worn on the outer side of the tread but near new on the inside. As a Boxster owner, I find this odd because Boxster owners normally see wear the other way around (inside worn first due to negative camber of the rear wheels).

Is this outer wear normal for a 996TT?

The dealer has aligned the 996TT's wheels twice in the past 2 years with the new tires coming in between the alignments. The 2nd alignment was just earlier this year and I can't see it having destroyed the tires so badly. Part of me thinks that the 1st of the recent alignments was perhaps bad.

I am replacing the oddly worn rear tires when I take over the car. I am worried about future tire wear in the 996TT and ruining the new tires right away like the previous owner has.

Related, I'd like to also ask: is the standard wheel alignment harsh on the rear tires in pursuit of maximum handling? If so, is there a modified alignment setup one can choose to extend tire life at the expense of some of that optimal handling? And if there is such a modified alignment, what sort of degradation in handling should I watch out for?

[1999Porsche911]

From my username, many would know that I'm a current 986 owner, but I'm also a new member of the 996TT club(!)

The 996TT I'm getting has new but oddly worn rear tires. After less that 4000 mi, the rear tires are excessively worn on the outer side of the tread but near new on the inside. As a Boxster owner, I find this odd because Boxster owners normally see wear the other way around (inside worn first due to negative camber of the rear wheels).

Is this outer wear normal for a 996TT?

The dealer has aligned the 996TT's wheels twice in the past 2 years with the new tires coming in between the alignments. The 2nd alignment was just earlier this year and I can't see it having destroyed the tires so badly. Part of me thinks that the 1st of the recent alignments was perhaps bad.

I am replacing the oddly worn rear tires when I take over the car. I am worried about future tire wear in the 996TT and ruining the new tires right away like the previous owner has.

Related, I'd like to also ask: is the standard wheel alignment harsh on the rear tires in pursuit of maximum handling? If so, is there a modified alignment setup one can choose to extend tire life at the expense of some of that optimal handling? And if there is such a modified alignment, what sort of degradation in handling should I watch out for?

Did you get a printout of the alignment? Sounds like they dialed in positive camber rather than negative. Any alignment shop can quickly identify whether your camber is positive. If it is, rapid acceleration will make the outside half of the tires wear even more.

If you bought the car and the tires were already worn on the outside, maybe the previous owner remounted the tires to the wheels.

Edited July 1, 2009 by 1999Porsche911

[wross996TT]

First to answer your question...it is not normal. As 1999 says usually folks have negative camber set-up (as it comes from the factory). Second...IMHO, you really should think twice about alignment for economy vs. handling...you have a 400+ hp car with some serious torque. Only takes one poor decision to cost a lot more than a set of tires. Third (if the tires were not remounted), the problem could be suspension link related...I would get it inspected. Oh and how is the tire pressure?

Edited July 1, 2009 by wross996TT

[Richard Hamilton]

Could be too much toe in, or a combination of too much toe and not enough negative camber. The tyres should wear evenly if it it set up to the factory specs. I just changed my rears (Conti SC2s) after 7000 miles, and they were worn evenly across the tread. An alignment is only as good as the operator. Try another shop.

[Boxxy]

Could be too much toe in, or a combination of too much toe and not enough negative camber. The tyres should wear evenly if it it set up to the factory specs. I just changed my rears (Conti SC2s) after 7000 miles, and they were worn evenly across the tread. An alignment is only as good as the operator. Try another shop.

Wow, only 7000 mi? I've started another thread on mileage out of new tires but I find your lack of tire life alarming. Maybe you track the car?

[Richard Hamilton]

No, I haven't tracked it at all (yet). I used to get about 12,000 miles from a pair of rears on my '98 C2, so maybe that's a useful comparison for you, although I ran Michelins and Pirellis on my C2. I always keep a good check on the alignment, and stick to the factory recommended specs. I hear that the Contis wear quite quickly on the Turbo, but I stuck with them as the fronts were like new after the 7000 miles, and I wanted to get more use out of them. I'm not a believer of mix-and-match on these cars. Next time, I'll replace them all with something different, but I don't know what yet. I should point out that I'm in the UK, so the conditions are probably a bit different - we don't have so many straight roads over here!