Tires worn out

[jwilbur1]

My '03 C4S has Continental tires and they are worn out after only 8600 miles. I don't drive the car alot, but when I do I have often done "spirited driving" on windy roads nearby.

Are the Continental tires that soft? Anyone else worn out tires this quickly?

And is there any consensus on the best replacement tires with decent grip and better longevity?

Thx for any input!

[djantlive]

Max performance tires wear about around 10k. If you drive aggressively, 8600 is expected.

Do you check tire pressure monthly? Are wears even?

Check tirerack for ratings. Michellin Pilot Sport and Pirelli Zero are amongst favorites. If tire wear is hurting your budget, get some less agressive tires that normally are put on sports sedans like Bridgestone 750.

[1999Porsche911]

You didn't mention which tires front or rear (or both). The front tires should be fine for 20 -30,000 miles. The rears, however, as mentioned above may get approximately 10,000 miles out of them. The wear on the rears will be in the inside half of the tire and the outside half will look fine. It is not uncommon to get all the way down to the belt on the rears. This is due to the negative camber setting on the rear.

High speed straight driving is the worse for the back tires because of this setup. During quick accceleration, the back of the car is lowered which causes the tire to lie flat on the pavement. Anything less that hard acceleration will allow the tires to ride more on the inside half.

You cannot get a long lasting tire AND good traction. A trade off has to be made. I have tried all the popular tires out there and have settled for the Bridgestone Potenza RE 750. I have yet to find a better traction street tire, hot or cold, wet or dry.

[geoff]

Not sure which Conti's / sizes you've got. My '01 Boxster came with 18" OEM ContiSport N1 rated tires. Rears (original) wore out at about 27.5K miles. Still on the original fronts at 33+K miles. Lots of canyon driving. Not much time over 100 MPH. No track / autocross

I've heard Conti's are harder, rubber-wise, and typically last longer than most other brands. Tradeoff is performance, comfort, noise, etc. Rears wear out faster than fronts typically because all engine power is transferred directly to rear wheels, while fronts just steer and brake (somewhat oversimplified, but you get the idea).

Alignment and correct pressure seem to affect how long tires last.

Like they say, your mileage may vary...

[acourvil]

I have tried all the popular tires out there and have settled for the Bridgestone Potenza RE 750.  I have yet to find a better traction street tire, hot or cold, wet or dry.

Are the RE 750s N rated (approved by Porsche)? I have them on my BMW 540, and I like them.

[C4S Surgeon]

I have the p-zeros, got 25k out of the fronts and 15k the rears, that includes track days too.

[1999Porsche911]

They are not N rated that I know of. Don't fall for that rating as a requirement for tires for your Porsche. 4 of the P-cars I hang with use them and we love them. I am on my second set.

Edited January 6, 2005 by 1999Porsche911

[Richard Hamilton]

Try www.mytyres.co.uk - select the tyre size and speed rating to search, select the tyre you are interested in, and click on the reifentest.com link. They give grip and wear ratings for most of the N-rated tyres. (Note: 1=best 6=worst). You can get to the site via www.tyretest.com but doesn't seem to include info for some tyres (P-Zero Rossos, for example)

I doubt if you would get 30k miles from the fronts of a C4, as they tend to wear more than the C2 and Boxster. 8500 from the rears is pretty poor. I got 12000 from a set of rear Conti's on my 993, with some spirited driving on our winding English roads.

Is the wear perfectly even? - they might have scrubbed out early if the alignment wasn't correct. You should get this checked at least once every couple of years, although lots of people have it done annually.

Edited January 6, 2005 by Richard Hamilton

[jwilbur1]

I checked the tire pressure every 1 to 2 months but I will be checking weekly now! The dealer caught the tire wear problem at the annual maintenance inspection, so I haven't seen the tires to check for even wear.

Thanks for the input!

Max performance tires wear about around 10k.  If you drive aggressively, 8600 is expected.

Do you check tire pressure monthly?  Are wears even?

Check tirerack for ratings.  Michellin Pilot Sport and Pirelli Zero are amongst favorites.  If tire wear is hurting your budget, get some less agressive tires that normally are put on sports sedans like Bridgestone 750.

<{POST_SNAPBACK}>

[jwilbur1]

It was the rear tires only. You make an interesting point about the negative camber of the rear tires. I didn't realize that but it makes sense.

You say you settled for the Bridgestones and they are the best handling- does that mean you expect the least amount of tire wear from them?

Thanks for your info.

You didn't mention which tires front or rear (or both).  The front tires should be fine for 20 -30,000 miles.  The rears, however, as mentioned above may get approximately 10,000 miles out of them.  The wear on the rears will be in the inside half of the tire and the outside half will look fine.  It is not uncommon to get all the way down to the belt on the rears.  This is due to the negative camber setting on the rear.

High speed straight driving is the worse for the back tires because of this setup.  During quick accceleration, the back of the car is lowered which causes the tire to lie flat on the pavement.  Anything less that hard acceleration will allow the tires to ride more on the inside half. 

You cannot get a long lasting tire AND good traction.  A trade off has to be made.  I have tried all the popular tires out there and have settled for the Bridgestone Potenza RE 750.  I have yet to find a better traction street tire, hot or cold, wet or dry.

<{POST_SNAPBACK}>

[1999Porsche911]

I get about 10,000 out of the RE 750's, althought I pushed the last set to 12,000 because I was on the otherside of the country when the SHOULD have been replaced. I replace the fronts about every 25,000 -30,000.

Edited January 6, 2005 by 1999Porsche911

[jwilbur1]

Geoff,

I don't remember the type of Continental and can't check at the moment because the car is still at the dealer's for the yearly maintenance. I believe the size of the rear tires is 295-30ZR18. Also since my car is a 4S the front tires get some of the power, but not a whole lot in normal conditions.

I plan to lift the rear of the car onto jacks as explained on a recent thread and take the tires/wheels to Wheel Works to have the new tires mounted. I haven't decided which tires to get yet.

Not sure which Conti's / sizes you've got.  My '01 Boxster came with 18" OEM ContiSport N1 rated tires.  Rears (original) wore out at about 27.5K miles.  Still on the original fronts at 33+K miles.  Lots of canyon driving.  Not much time over 100 MPH.  No track / autocross

I've heard Conti's are harder, rubber-wise, and typically last longer than most other brands.  Tradeoff is performance, comfort, noise, etc.  Rears wear out faster than fronts typically because all engine power is transferred directly to rear wheels, while fronts just steer and brake (somewhat oversimplified, but you get the idea).

Alignment and correct pressure seem to affect how long tires last.

Like they say, your mileage may vary...

<{POST_SNAPBACK}>

[jwilbur1]

Thanks for the link, I will check it out! 12,000 miles sonds pretty good right now.

The wear is evidently on the inside of the 2 rear tires. According to the Service Advisor, 1 of the 2 rears is down to the cord, the other is in need of replancement also, but not down to the cord. I will ask about the alignment, but I suspect it is ok since they didn't mention it to me.

Try www.mytyres.co.uk - select the tyre size and speed rating to search, select the tyre you are interested in, and click on the reifentest.com link.  They give grip and wear ratings for most of the N-rated tyres. (Note: 1=best 6=worst).  You can get to the site via www.tyretest.com but doesn't seem to include info for some tyres (P-Zero Rossos, for example)

I doubt if you would get 30k miles from the fronts of a C4, as they tend to wear more than the C2 and Boxster.  8500 from the rears is pretty poor. I got 12000  from a set of rear Conti's on my 993, with some spirited driving on our winding English roads.

Is the wear perfectly even? - they might have scrubbed out early if the alignment wasn't correct.  You should get this checked at least once every couple of years, although lots of people have it done annually.

<{POST_SNAPBACK}>

[jwilbur1]

Update, I got my car back from the dealer. The tires are Continental Sport Contact 2. The rears are somewhat worn, but there is still a good 1/8" of tread at the most worn part of the tires until reaching the wear strip.

Since I need a 295/30 18 size, I will be ordering the Michelin PS2's. They seem to have universally good reviews.

My front tires still have quite a bit of tread.

Thanks to all for your kind input.

[LVDell]

correct me if I am wrong, but shouldn't you have matching tires front AND rear. I don't think it is reccomended to have differing tread patterns on the front than on the rear. Personally I would order the same tires for the rear and then the next change will probably be in line for all 4 when you can swithc to a new marque.

[jwilbur1]

Good point, I hadn't thought of a problem having different types of tires front and back. Plus the Conti's are cheaper...

correct me if I am wrong, but shouldn't you have matching tires front AND rear.  I don't think it is reccomended to have differing tread patterns on the front than on the rear.  Personally I would order the same tires for the rear and then the next change will probably be in line for all 4 when you can swithc to a new marque.

<{POST_SNAPBACK}>

[magcuda]

your alignment should be checked within the first 2000 miles on the car. I used to put it through on warranty as an adjustment that was covered under 2500 miles. the suspension settles and will cause the inside of the tire to wear. the porsche feels best with the recc tires by porsche, they are recc for a reason. also the alignment should be checked every year, even if you don't drive it it is still sitting on the suspension. the proper alignment is done by weighting the car with sandbags, if this is not done the correct settings are not met :drive:

[jwilbur1]

That answers my next question. The dealer said they wanted to align the car after I got the new tires installed. It is supposed to be a 4 hour procedure and costs $200. If it really does take 4 hours, the price seems fair.

I just took a closer look at the tires, the inside edge of the RR tire is very worn. The first groove on the inside has a fair amount of treadware left, maybe 1/8" but the edge of the tire convinced me to order some Conti's from tire rack. They will be drop-shipped to a Firestone store nearby which is supposed to accept drop ships and charges $20 per tire to mount and balance. The tires are $298 each plus $32 shipping.

Thanks again to all who provided advise. I'll provide an update when the tires are installed if anyone is interested.

your alignment should be checked within the first 2000 miles on the car. I used to put it through on warranty as an adjustment that was covered under 2500 miles. the suspension settles and will cause the inside of the tire to wear. the porsche feels  best with the recc tires by porsche, they are recc for a reason. also the alignment should be checked every year, even if you don't drive it it is still sitting on the suspension. the proper alignment is done by weighting the car with sandbags, if this is not done the correct settings are not met :drive:

<{POST_SNAPBACK}>

[Loren]

My advice (for what it's worth)...

1. Make sure that the tire installer has worked on Porsche's before. Some of these guys look at them and don't have a clue how to lift one.

2. Make sure that their tire mounting machine does not touch the rims. Like a Hunter TC 350 Tire Mounting Machine.

3. Make sure they have a high end Hunter GSP 9700 Road Force Measurement Wheel Balancer or better.

4. Find a good speed/alignment shop. A professional 4 wheel alignment should run about $160. These are usually the folks that do all the race cars in the area.

[1999Porsche911]

Changed

Edited January 7, 2005 by 1999Porsche911

[magcuda]

I agree with Loren, are your wheels only worth $20 each for mounting tires. it takes a while to be careful with this wheels even with the proper equipment. 4 hours is about right for a street alignment, track alignments are usually more aggressive ane if your main goal is track then tire wear is not an issue. the main thing is that the Porsche specs are for a weighted car.