A1EK

Hi Guys

My rear tyres are 255 x 35 x 18" and I have always found that they tend to wear in the middle 1 or 2mm down slightly faster then the edges. First thoughts are that the tyre is over inflated however if I lower the pressure it dosent really make that much difference. A garage told me that most cars with wide tyres have this problem including BMW's and theres not anything to worry about.
I inflate usually between 30 to 34 PSI but even right down to 20 theres not much difference. Im not concerned as despite my car being lowered the tyres wear perfectly even otherwise and I would be more worried if one edge was wearing faster etc but they don't thankfully.

Does anyone else with similar size tyres find the same?

thanks...

mint

What brand tires you run?

In general, rears should be around 36 +/- a few PSI. I can tell you that running that low of a pressure coupled with the weight of these cars is asking for a bent wheel. So that's actually kind of strange that the middle wears faster than the edges since you most likely need to increase the pressure.

Don't think a worn suspension component would wear the middle faster but I know more about the front end than the multilink arms in the back. Might be wrong. Got any alignment specs?

dlbehrns

too much air/over inflation. call a tire shop and ask. I run my set of Hankooks at 32-33 and the same for my Toyo Proxy 4s and they wear very evenly. If you don't believe me lower the pressure and see what happens. And, don't you have a little picture somewhere on your car that tells you what pressures should be. check your owners manual as well. I don't mean to be sarcastic but this is DIY class 101.

A1EK

? You must have not read my initial post as I've answered all your points, its not overinflation....

Josh K

So you've taken a brand new, unused set of tires and run them at a lower pressure for the same time as the tires exhibiting the faster wearing in the middle and the wear is consistent? You can only rule out overinflation if you've done an equal time comparison beginning with unused tires at each pressure. Lowering the pressure for a month and eyeballing it (even with a ruler) doesn't really mean anything if you're starting with a tire that already has uneven wear.

MarcusF

There's a long winded treatise on this at my website (everything there is a bit long) but the short answer is- buy an infrared pyrometer and measure the temperature across the tire. A pyrometer will tell you the correct pressure for those tires on those rims with that alignment on that car. A pyrometer will last a lifetime and pay for itself rather quickly in tire savings. This is especially true for those who go through $1K in tires every 18 months.

The writeup at Signal to Noise is entitled The Correct Tire Pressure

turbocad6

what he said^^ also check the tire specs and the specified rim size range for that particular tire... as the profile goes down this becomes much more critical and you don't want a 35 series tire that is on a rim that's inside or outside of the specified acceptable rim range for that tire

A1EK

Now that sounds like a really good solution.!
If I feel the tire it does feel cooler on the edges

A1EK

I've run the tires with 20psi for 3 months and its not over inflation....??

Josh K

A brand new set of tires run at 20 psi for 3 months still wore more in the middle?