Uneven Tire Wear on Coupe?

[Stu Segal]

I've been running my tires at the recommended pressure - 30 cold - and I notice uneven wear.

20,000 miles on tires. Rear tires are wearing out right down the centers, and front tires are wearing out on the edges.

Anyone have any insight, or similar experience?

Thanks. . . . .Stu

[C-Kwik]

Fairly normal. While the pressure is fine, speculation is that the cause is putting the widest tire that will fit on a given wheel is causing the tire to bow out slightly in the center. But I would be happy just being able to get 20,000 miles out of those tires. I think I replaced mine at about 14,000.

[rydwhite]

Tire wear has been a common themed problem on the G. I had some extremely bad tire wear on my tires and finally changed them out at 25k. The camber setting on the rear caused some odd wear. I would double check the camber on the rear and get an alignment when you get new tires.

[Rex]

As an outisde observer ...

I agree with C-Kwik, if you're getting >20k out of tires, on a perfromance car, you're doing real well. I'm happy to get 12-15k from tires on my car.

[C-Kwik]

Come to think of it though, did you have the 17's or 18's? I don't think the 17's run the Michelin PS so depending on what tire it comes with, it could make a difference on wear. The 17's come with All-seasons if I'm not mistaken and would likely have better wear ratings than the PS's. If you have the PS's though and got 20K, consider yourself lucky.

[tom hert]

My 04 coup came with GY 17" and I changed out at 40K with the fronts still at 50%. The rears were worn uneven (center wear). I don't understand the low mileage from others.

[Q45tech]

Besides driving style: accelerations brakes per mile.

Road composition asphalt vs concrete...........local temperature conditions, speed.

Not unusal to have a 100% variation range on the same tire on the same car.Same with brake pad/rotor life and mpg.

Some wear cars out in 70k some can drive the same car 300,000 miles.

[PoorManQ45]

Rear tires are wearing out right down the centers, and front tires are wearing out on the edges.

Thanks. . . . .Stu

This is a little late response but here's a tip.

The rears are overinflated, the fronts are underinflated

[C-Kwik]

This is a little late response but here's a tip.

The rears are overinflated, the fronts are underinflated

Most people with the 18 inch wheels have had the problem with the rears regardless of the tire pressure. My own speculation is that squeezing a 245 wide tire onto a 8 inch wheel is causing the middle of the tread to bow out slightly. I had the tire pressure on my Michelin PS rear tires set to 30 psi, which is relatively low nd it still wore out the center first. My S03's are starting to show similar signs on the rear.

[PoorManQ45]

Try dropping it down to ~25psi and see what happens

[C-Kwik]

I get a loud annoying beep and a light that comes on my dash. The TPMS triggers at 28 psi. And I would not even bother running a tire at that low a pressure. Fuel consumption and safety are much more important to me than tire wear. I got nearly 14,000 miles out of the Michelins so I'm happy. I was barely getting that out of my tires on my 240sx before.

[szh]

Try dropping it down to ~25psi and see what happens

NO! Or certainly not for very long at all!

Never drop the tire pressure to the point where the load (static and dynamic) exceeds the load index of the tire at that pressure. This is a serious safety hazard.

Z

[PoorManQ45]

Fuel consumption and safety are much more important to me than tire wear.

Safety is an issue if your tires are over inflated too, which is what causes the center to wear more. you braking distance is greatly increased.

NO! Or certainly not for very long at all!

Never drop the tire pressure to the point where the load (static and dynamic) exceeds the load index of the tire at that pressure. This is a serious safety hazard.

Z

Yep, sorry I didn't make that clear. But like I said, running with too much pressure can be just as unsafe as running with too little. Just think about all those times that you stopped "just short" of hitting someone, and then add ~5~10ft to it. Would you have hit them?

[szh]

Safety is an issue if your tires are over inflated too, which is what causes the center to wear more.

If grossly over-inflated, yes, this is correct.

you braking distance is greatly increased.

Sorry, not exactly correct. As long as the over-inflation is minor, and does not cause the profile and section width to change dramatically, the braking distance is not affected "greatly". Running up to 4 to 6 psi higher than the "manufacturers recommendation" is okay as long as you are still well below the tires max rated pressure.

For example, on my M45, the "recommended" pressure is 32psi. I use tires that have a 51 psi max inflation pressure. So, running at 36 psi gives me a simple margin for error (the usual monthly drop of 1 to 2 psi, measurement error, etc.), brings me to the value that the tire load index is measured at (nominally 36psi) and does not get close to the max inflation pressure (51 psi). The "center wear" does not increase much (since the tire is still flat on the ground - the tire section width and profile are normal.)

A very reasonable trade-off.

Z

[PoorManQ45]

Sorry, not exactly correct. As long as the over-inflation is minor, and does not cause the profile and section width to change dramatically, the braking distance is not affected "greatly".

Z

Well, from what he said about the center wearing out faster, this would lead me to believe that the tread block was dramatically reduces

[szh]

Well, from what he said about the center wearing out faster, this would lead me to believe that the tread block was dramatically reduces

I know ... I read that too!

I agree with the speculations that the tire is bowing out or that the camber is causing havoc. I suspect it also has a lot to do with the tire make and model. On my M45, with the 7.5" width rims, the 245/45-18 is not showing the same center wear.

My normal suggestion would be to front-back rotate much more often to even out the wear. But, this is not convenient on the G35 Coupe given its asymmetric rims (different offsets and maybe even width depending on whether he has the 17" or 18" rims) as I recall.

Z

[C-Kwik]

Safety is an issue if your tires are over inflated too, which is what causes the center to wear more. you braking distance is greatly increased.

But the safety I speak of is not an issue with traction, but of tire failure. Higher pressure up to the maximum pressure generally increases the load capability. Running slightly low pressure may be okay for most street driving, but under hard driving, it can cause excessive heat and cause a failure. Try driving on a completely flat tire for a mile then touch the tire. It will be quite hot to the touch.

[J-Owner]

Ok, so I am confused on the proper PSI to have in my tires.

I am currently running 31 psi in all four tires on my '05 coupe. Is that ok? Or should I be running higher?

Could someone clarify. Thanks.Brandon

[PoorManQ45]

Are you running OEM tires? If so, check the door jam, or wherever that sticker is located

[BippuBoss]

different wear just means that some of your tires are over inflated and some underinflated.

[Sentientbydesign]

different wear just means that some of your tires are over inflated and some underinflated.

Sorry BippuBoss, but that's not the case. The wear issue in the front is caused mainly by negative camber and any slight toe error will compound that problem.

The rears still perplex me though. Running 30-35 PSI in the rear should not cause center wear. It is possible that the negative camber in the rear is also the culprit for the center wear, but not likely.

[C-Kwik]

This thread is like 3 years old. Wow. Anyways, since this thread, much observation can be made. I've probably mentioned it before, but starting with 05, Nissan/Infiniti bumped up the width of the rear wheels on the 19 inchers while keeping the tire width the same. They also did this on all the non-track/GT wheels as of 06. I haven't heard the same complaints about the center of the rear tires experiencing wear first for the cars fitted with the newly widened wheels. I highly doubt the issue was related to inflation.

[Sentientbydesign]

Thank you for the insight. I will check this set of tires to verify that they are ok.

My last set were completely bald in the centers (bought it from previous owner that way).

What is the remedy for the inner feathering on the fronts? Just an alignment with the "highest" camber value attainable?