Does anybody know what causes this?

[LVR]

Hi,

My independent engineer has alerted me to the unusual tyre wear on the rear shown here, where the centre of the tyre is worn and the edges are not.... and no, they have NOT been over inflated..

I think it is suspension related... are there any experts out there able to tell me why this is happening?

You can also see that the tyres are sitting on the inside edge when car is stopped.. yet there is no wear on the inside edges to suggest camber/toe is out.

TIA

[Sedoy]

1. Tire pressure to high
2. Alignment
3. Suspension (if uneven over perimeter of tire, causing wheel jumping)
4. Wheel problem

[China Man]

I have the same problems of my style 87's wearing the same way, however the stealer was never able to diagnose a problem (surprise) .... seems many have this problem (?) ... my buddy's 4.6is has the same issue, and not due to overinflated tires, either ...

[dkl]

Looks like over-inflation. What pressure are you running at? Mine was wearing evenly when I run about 34psi. But as soon as I pump it up to ~36psi, I got the same wear pattern as shown in your pictures on my last set of Bridgestone Turanza. Radial tires alway look normal once the car is stopped, no matter how much pressure you have in them...so you can't really tell just by looking at it. The contact patch at standstill and while rolling is NOT the same.

[rayxi]

Are you on OEM rims? A wide low profile tire might bend up in the middle of the tread if mounted on a wider rim than the tire was designed for.

[LVR]

Re overinflation, we have been monitoring them at 28psi cold and 29.5psi warm, so that's out as the max recommended is 32psi. There is no load on the rear such as trailers, caravans, heavy cargo and I generally run at half a tank of petrol.

We also believe the rear wheel alignment is correct at rest.The tyres are OEM Michelins, the wheels are OEM 4.8is rims and no alterations have been made to the suspension/ride heights in any way. They currently have 33,000kms of use and the fronts are evenly worn

We have noticed that a there's a lot of twisting of the tread blocks right next to the wear area (the last photo) yet elsewhere there isn't.

[gonzjed]

It's called cupping...too much air in your tires. Your going to have to get a new set of tires and monitor the heck out of your tire pressures.

[X5Jay]

I'd recommend talking with someone over at Michelin Tire about this, let them have a look at your pics, and see what they have to say. Could simply be just how those tires wear on an X5, i.e. normal. How many miles are on them?

[Tomaz]

Looks like too much air to me. Is your tire gage calibrated? Does your drive have a change in altitude? Are you checking the pressure of the tires cold?

[LVR]

As I have said a number of times, over inflation is not the reason.

We have been investigating 'dynamic supension movement' which appears to be the toe in and camber of the wheel changes during cornering depending on the body position.

re Michelin, thanks for that, we have sent copies off to them yesterday and am awaiting feedback.