Replacing tires - one axel or both?

[SteveGraham]

My 05 TTS cab has 14k miles and it's time to change the rear tires. The fronts are questionable, with 4/32 inside and 5.5/32 center tread remaining. I plan on purchasing Michelin PS which are the OEMs the car came with. The Porsche dealer believes I can continue to ride on the fronts another 5k+ miles, and I understand it is not unusual for the rears to provide only 50% of the mileage from the fronts, but I have some questions and would like some thoughts & suggestions:

1. If I replace just the rear axle, how negatively, if any, will the handling be affected;

2. Should I just replace all four tires for both safety and handling reasons, or try to max out tire wear from the fronts?

Thanks in advance, Steve. :drive:

[White987S]

Steve, I agree with the dealership.

[Beecher]

Steve, I replaced the rears on my 03 TT coupe at 7500 miles. The car handled fine with the old fronts still in place. I am thinking they will last until the rears go at 15,000 miles. Turbos are hard on rear tires!

[SteveGraham]

Thanks Beecher and White987s. However, I already have 14k on the fronts, and I've always changed all four tires at a time. I'm just not used to changing only one axle. Seems like the tires will forever "not be matched". I'm probably just nervous for no good reason. Thanks again.

[alpha]

Steve -- on other forums there is a lot of talk about the rears lasting only half as long as the fronts, with people commonly needin two sets of rears for every one set of fronts. Based on those discussions, seems like a typical situation. The main concern seems to be about different type tires front to rear, with the consensus opinion to stay with the same brand-type of tire all around to maintain consistent handling.

[petertobin]

My understanding of this is that it depends on the amount of wear on the fonts - different rolling radius can badly effect PSM; I personally know someone that had this issue (replaced rears only - car was horrid to drive "quickly" - fronts were about 50% worn) and have read about it in other forums.

PS beleive same brand of tyres used so that was not the issue.....

Edited November 20, 2007 by petertobin