redwhiteblue

I have mich pilot sport a/s on my car and that said I drive very aggressively and understand I am going to burn through tires quickly which is ok. However I was expecting longer life on this a/s pair I got about 7k ago with a tread life of 400 v. the dunlops summers 01s I had with a tread life of 220-which still lasted 10k on the rears/20k fronts.

Anyway in the middle of my tires I have about 6/32s left on both tires-I rotated them once so they have evenly wore over the past 7k miles. The thing is that is the middle two linear grooves. Each side of the tire has slashed grooves that run at a 45 degree angle-sorry I cant explain better-if you look at a pic of pilot sport tires you know what I mean.

Anyway they wear WAY slower on both sides of the tire and are still at like 8-9/32s-the tires came with 10/32s everywhere

I keep the pressure maybe a BIT higher than normal 39-49 rear and 35-36 front comapred to rec 36 rear and 32 fronts.

I have read reviews similar to mine about middle wear but I am thinking did my tire pressure affect middle wear that much from being a couple PSI higher? I simply prefer a bit higher pressure for handling but will change back if it is that bad-any thoughts.

kscarrol

Yes, over inflating tires will cause more wear in the middle of the tread while under inflated tires will wear quicker on the edges. Doesn't seem like a few pounds would cause that big of an issue though, but then I'm no tire expert. I did stay at a Holiday Inn Express last night though!

Rudy

That's enough for me!

HotLap

Isn't the recommended tire pressure 32lbs. for both front and rear? If that is the case then your rear appears to be overinflated (no pun intended ) but even the fronts at 36lbs would still wear a bit more in the center...shouldn't be that noticeable though.

SLORider

You may have thought of this but your gauge is another variable. Tire gauges can vary in accuracy and also over time. If you've dropped it or don't check it against another one occasionally it can be off by a few pounds.
If your checking your pressures at home with cold tires then running hard and heating up the air the pressures in the tires are going to go up further. I wonder what 49 pounds in driving tires warms up to after a few 'hot laps'?
I would think the tires would perform better if they had the ability to flex more. I just got through doing some testing on my motorcycle and it took a while to find the right tire pressure combo front and rear. I go by the tire makers rating not the m/c manufacturer and it seems to work.
Damn, I've rambled again.

redwhiteblue

No bmw recomends 36 rear and 32 fronts-however the other thought I had which is why I initially increased it to 40 and 36 was that bmw designs their suspension for the run-flat tires that come equipped with a sport package and run flats inherently have stiffer sidewalls-so in order to achieve a similar stiffness one would have to inflate a bit higher.

Whether or not this is accurate who knows but I do know bmw designs their suspension on sport models with run flats specifically for run flats-

I went to non-runflats and bumped the pressure a bit. But I did change guages and double checked today and with the cooler whether it actually dropped to 35 rear and near 31 front so obviously it was not the over inflation-it is back to almost standard.

And obviously I understand the biggest contact path is in the center of the tire so it makes sense to wear more but was thinking it wouldnt wear that quickly-ahhww I tried to drive slow and proper for about 2 days and just couldnt handle it-I just need to drive a sport bimmer constantly high spirited what can I say.

HotLap

I hear you...I can't even run the lawn mower on slow or medium....got to be cranking ALL the time Guess you'll just be getting new tires a bit more often! You may want to try another brand next time and see it they give you more miles?

monacobmw

Wear on the middle is always a strange thing and very rarely attributed to anything except overinflation. When you overinflate, you are effectively driving primarily on the middle of the tires. As you were "saving weight" on your car to provide a better ride, the highly inflated tires also give better mileage. The downside is the center wear issue.

A lot of us recommend the General Exclaim as a cheap, but good tire. Give it a try the next time you switch.

I have heard one complaint on quick treadwear on the GEs (I also heard two other good comments on GE treadwear), but mine are fine after 14k.

redwhiteblue

General exclaim? huh-never even heard of such a brand-will have to check it out, thanks a lot!

I highly doubt my 100 pounds of saved weight could cause my tires to be over inflated but who knows.

monacobmw

RedWhite, sorry, I did not mean to imply that the reduced weight had something to do with the overinflation. I was actually applauding you because the two together are more energy efficient for saving fuel. Less weight and less rolling resistence means better fuel economy. The downside to overinflation is the bumpy ride because you get no flex in the tire sides (especially if you have low profiles).

Take a look at tirerack.com. Everyone really likes these tires (as they rate them on tirerack). The tires are very cheap, and really good (and they come in a lot of sizes). Also check out some of the threads here on the GEs.

Good luck with your next set of tires.