Rear tires flat
 

Both rear tires are worn down to the steel belts only on the inboard tread at the side wall. Any ideas as to the problem. thanks

Would need pics to really know. This thing doesn't happen overnight, could be a couple things.

First thoughts:
- extreme use
- under inflation
- over inflation


Most likely a combination of miles and inflation issues considering both went at the same time.

If you search "tire wear" you will see lots of threads on this. The X5 has a few degrees of negative camber, that is, the rear wheels tilt in wards. This causes excessive wear on the insides of the tires, and is more pronounced with the wider tires. The only things that can be done is to have a mechanic dial out as much camber as possible, and maintain your tire pressures to stated amount. If your tires are not unidirectional, you can have them reversed halfway through their lives.

^ true

But dialing out camber will also result in worse handling.

true, but only at the extreme limits.