My C2 becomes a tire eater

[tt2001]

My 99' C2 becomes a tire eater. Few months ago I changed my rear tires to Kumbo MX 18" and they only last for three month around 4000miles. Then I changed them back to P Zero and did the four wheel alignment ,now only 3000 miles they almost gone again. Both rear tires wear evenly. however, I always find my rear bumper has black particles and stink smell when park into grage, which are obvious the rear tires worn out violently.

I live in Southern California, not a aggressively driver.

Thanks for any input.

[Richard Hamilton]

I wonder if it could be a differential problem. Do you feel or hear any rear tyre scrub in slow speed tight turns?

[Loren]

Another question...

Does your car have Traction Control (TC)?

and/or Limited Slip Differential (LSD)?

[ar38070]

What are the alignment numbers? In particular toe. Who did the alignment? What equipment did they use?

[tt2001]

Thank you everyone, alignment done by my local grage who fixing Porsche and other Europen cars. I printed out the alignment data from this site and they using a computerize equipment to go the job. My '99 C2 has TC, which always on, if it's correct? or I better turn it off.

There's screech sound from the rear tires in slow turns only when the tire traction was low.

[Loren]

Any spacers or non Porsche wheels? If so how large are the spacers and what is the size and offset of the wheels?

If you have TC then you likely have a LSD. You should not get any screeching except when a rear wheel is slipping.

[tt2001]

Any spacers or non Porsche wheels? If so how large are the spacers and what is the size and offset of the wheels?

If you have TC then you likely have a LSD. You should not get any screeching except when a rear wheel is slipping.

<{POST_SNAPBACK}>

Hi Loren, Thanks again.

Everything are origial , I did not add/change anything. I think I'll need go to the dealer and let them to check this time. :( (or it might be the last alignment did do right.)

[Loren]

Yeah, something must not be right especially if they both wear fast. Cars with TC and LSD don't usually get poorer mileage out their tires unless they track the car a lot. 996's go through rears about twice as fast as the fronts but still even aggressive drivers (like me) still get 9000 - 11000 miles on the rears. I'm the guy that got 9000 ;)

[djantlive]

What's tire pressure? I've heard 44 psi tends to wear out center fast and 40 psi is a good setting.

[1999Porsche911]

You definately have something wrong. The proper allignment balancing and 44 psi will not wear the tires out like that. When the rear tires wear, they will ALWAYS wear more on the inside first. Do you have the printout of the allignment specs AFTER it was done?

[tt2001]

The problem has been found.

It was caused by wrong rear TOE-IN adjustment, there's 1/2 inch over so the rear tires always dragged and worn very fast. It's cuased me two set of rear tires with in four months. OUCH. :angry: