Rear tire wear

Pilot Sport N1 (Rib). 265/35/18. 16,500 miles. 90% of them at 40 psi. Last few miles at 42 psi. And it looks like 40 psi may be too much. Thoughts? (Outside is on left of photo)

I can't believe you would drive them even nearly this bad.

Yeh, I know, but I don't drive in the rain, and I've only been using the car intown. And I've kept a pretty close eye on them. New PS N1's going on Monday.

If that is from street driving only, your rear camber is way off. At least put some negative camber on the car.

I'd say you are a man that gets his money's worth!! People pay a lot of money for slicks. Sell 'em on Ebay!!!

Yes, street driving, and a few AX's. -1.4 camber on rear.

Maybe a shave to much pressure since the cord is showing in the middle but dear God, what in the world are you doing driving around till the cords for? Come on Kevin, if you wanted slicks so bad, you should have just got the damn Hoosier

FWIW, the shadows in the pics are somewhat concealing the additional wear on the inner edges, and it is not excessive, but it is noticable.

Okay, now that I've been scolded, can we talk about tire pressures?

Honestly I think you pressure is fine. I run between 38-40 in the rear in mine. But that wear you have is a result of alignment more than pressure. Just notice the incremental wear pattern from left to right.

LOL Well I run 40 in the rear and 38 in the front, and my tires have lasted about 14,000miles and still look pretty good. I have Goodyear gs d3 or whatever they are called.

I don't know why, but just the way you put that line "I have Goodyear gs d3 or whatever they are called ." made me laugh so hard my eyes are watering!

i do 40-42 psi in rear. your wear seems very even to me. my centers were worn more when i replaced it at 25k mi. i do mostly highway.

I run at 42 and get about 22K out of the rears. I wish my tires wore as evenly as yours. Mine wear out on the inside first, especially the right rear.

Dell, aren't rears supposed to wear less on the outside (left of pic) and more on the inside (right of pic)? I mean, I've got -1.4 on the rear, and the wear seems pretty fair to me. I prefer the lower pressures in the rear for understeer purposes anyway. Anyone other than El Torr running as much as 38 in the front? Anyone run 36f/38r ?

I run exactly what you mention Kevin (36/38). Like I said your wear look right. It has more tread (if can even call it that at this stage) on the outside than the inside and is progressive in its wear from out to in. I don't see much wrong with your wear other than maybe a shave too much pressure.

LMAO I didn't realize how funny it was, but I guess I know.. EXACTLY what they are called.

Dell, do you run 36/38 on the GT3 or the Cab? Or both? FWIW, they just got looking really bad in the last couple of weeks (300mi or so). Looking forward to the new treads on Monday (was supposed to get them yesterday, dadburnit).

Kevin, loving the new avatar! As for the pressures, I run the spec pressures in the 3, but in the cab I run the 36/38 combo.

Dell, just for the record....... I've heard GT3 pressures are 34/39. Is this correct? And I will definitely try 36/38...... may well be the hot setup.....

Pressures in the GT3 are 32/39.

I can't believe the milage some people get out of tires on a 996, 11,000 her and they looked that bad.

nice slicks

is it legal to run on the road with those???

No, it is not. In fact, those tires are so bald that you can't legally make a "tire swing" out of them!

My left rear PS2's looked "almost" that bad when I changed them out at 13K. On the bright side, compared to what it must have felt like for the last 1,000 miles, your car will ride like a Lexus sedan when you put on the new rubber.

Kevin, here's the problem: Once you put new tires on you are going to hear all sorts of other noises that are going to make you crazy thinking somthing is wrong with your 996. I recently replaced my tires (worse than yours) and now they are so quiet I can hear every other "scary" sound!!! Good luck!!

New treads! Bwahahahahahahahhaa!

I run 36/38 in my MY99. I have only had the car since October so I can't comment on the wear as I have not driven the car that much. The current set of tires has at least 8k in mileage and are pretty warn compared to your tires (I have the same Michilen Pilots) but the wear is even. Considering these tires did the 1 lap and then have 5 or 6K more in mileage I would say they have lasted well. I'm not sure what my camber is but I would say it's fairly aggressive (more than 1.4) as the PO set it up to be a track toy. With that pressure and my alignment, I can say the car is very neutral in Autocross as it is more than happy to produce trailing throttle oversteer if you over cook a corner entry. Pete

Hey Kevin, those tires look pretty good to me. The wear looks just about right on. Maybe a little too much pressure. I would get another 500 miles out of them. I run P-Zeros on a 2002 C2. Now run a tire pressure of 33/39 vs factory 36/44. If I get 5000-6000 miles out of my rears I consider myself lucky. I do not accelerate hard from stops. In fact I make a point not to. I feel my tire wear is from only driving this vehicle on mountain and canyon roads. This car never sees the freeway and rarely runs in a straight line. I think my excessive wear to the rears probably is increased by accelerating hard out of turns. Tom L 2002 C2

Which P-Zeros? Tire Rack has come with a tread life rating of 220 called the Rosso and some with 140, including the P-Zero Asimmetrico. The 140 ones must be a blast, but it might also explain your frequent need for new shoes. Michelin PS2 and Sport Rib are 220, although I realize you can really compare these numbers between brands.

Tom, I was nervous as all hell the last week or so driving on rears that worn. I don't think they would have made it another 100 mi! But now, with the brand spankin new PS N1's, I'm set for many, many happy ***-haulin miles......

DCP I am running P-Zero Rosso. Tom L 2002 C2

Kevin, was that tire inflated or deflated? Sorry, I can't see if the wheel was on or off. If the tire is inflated, I see there's a "cupped" center. Which means the wear in the center is not from over-inflation, but rather under-inflation. It's a weird situation on soft Hi-performance tires that my mechanic explained to me once, and recommended I increase psi to prevent the cupped-center wear. It's kinda complicated, but I'll try to explain if you are interested.

Cosmos, The tire is in fact mounted and inflated. I'm sure all of us that are running lower than factory pressures on rears would be interested in your mechanic's reasoning. Thanks.

Ok...this was for my BMW 540i which had cupped-center wear on the tires. I had always went with the factory recommended psi for all 4 tires. This is how he explained to me: Hi-performance tires are of soft rubber compound. (That also explains why when my car sits for a week, the steering shimmers at first drive until the tires warm up later on). If the pressure is not high enough, when the rubber warms up, it gets softer and expands. The center of the tire therefore "bulges" or curves out slightly, which means it wears more than the sides. When the car is parked and the tires cool down, the center goes back to its original shape, which is why it's cupped. His advice was to increase 2 or 3 psi to the tires, the higher pressure would help to "hold" the shape of the tire when it gets soft and expand. This will ensure a more even shape (or flat) of the tire that is in contact with the ground. At the time, it sounded weird and confusing to me, but since he was a good reputable BMW mechanic, I listen to his advice. I set my tire pressure higher, had to bear with the stiffer ride, BUT...I can tell you, my next set of tires then did NOT cup! (Although my rears still wore on the insides, that's German camber at its best.) That made me a believer, and I try not to underinflate tires. With the C4S however, the ride is just too hard to follow factory psi. I'm using +/- 33-40 and I'm watching the tire wear to see what I can learn.

Cos - that is strange, because I had the exact opposite experience. When I bought my car it had 6,450 miles on it and it had P-Zero Rosso tires on it. I ran 44 PSI in the rear and at 8,500 miles the center of the rear tires was worn much more than either the inside or outside edges. When I replaced the rear tires I ran 38 PSI and those tires lasted about 11,500 miles but the tire wear was much more even across the entire tire. I'm not saying that the BMW guy's theory was wrong, just saying that I experienced the exact opposite of what you experienced. Weird!

Tim, were your tires cupped in the center? If they were just worn on the center, then it was just over-inflation, as we all know it. What I explained above is for Cupped-centers. I'm no tire wear expert, but it worked for me, and now it makes sense what he explained to me. I had cupped a couple sets of tires before trying out his advice, and I have not have cupped tires after that. Coincidence? I think his theory makes sense.

Maybe I mis-understood your meaning of "cupped." I was assuming you meant that the center of the tires wore out more quickly than the inside or outside edges. If that is not what you meant by "cupped," then maybe we are talking about two entorely different things.

Tim, I am sorry I might have used the wrong term "cupped". I think cupped is normally used for worn spot on a tire due to struts or suspension issues. Anyway, if you look at the tire in the original post, the centerline of the tire is "concaved", unlike a regular "worn-in-the-center" tire caused by over-inflating, where the center is rounded, as in convexed. I'm not able to elaborate on this, as like I said, I'm no expert on tires. Maybe there are more knowledgeable members here who can comment on this. I would also like to know if what my BMW mechanic told me makes sense at all (I know it works somehow).