Tyre Pressures Correct But Middle of Tyre Worn. Advice?

[SebringMan]

Right, I have a BMW M3 of the E46 variety. The rear tyre wear is interesting, but the tyres did come on the car when I bought it. It is on Falken 453s on the rear.

The middle of the tyre is worn to just over 2mm but the outer parts are more like 3.5mm. The tyre pressures are correct (around 35PSI IIRC) and I have checked these both at the petrol pumps and with a digital tyre gauge.

The last owner seemed to think 31PSi was a good pressure to run the rear tyres at, with around 30 up front.

My questions is have others suffered this. It would be nice to know before I start marking the tyre up and playing around with tyre pressures in an attempt to even out the wear.

[SebringMan]

E-bmw said:

If all you have is 2mm in parts & do not know for sure the history/accuracy of the tyre pressures, I wouldn't bother.

Just ditch them & fir the correct tyres at the correct pressures, keep on top of them every week/fortnight & I suspect the next set will be just fine, if you check (and keep note of) the wear regularly you will see if there are any issues.

Cheers. I suspected it may be to do with the history of the tyres but I figured I may as well ask to save the new tyres going the same way should there be a known fault with the car or tyres .

When replacements are between £130-200 depending on brand it is not simply a matter of 'changing' them (255/35R19 size) . I normally do keep on top of pressures and tyre condition though mind you. Most my cars with new tyres seem to last quite some time.

[SebringMan]

Sheepshanks said:

My old Merc C270, that I mainly used for motorway cruising, wore the centres of the rear tyres and I ran them at the minimum stated pressures.

I did wonder if higher pressure would have been better and perhaps the tyre was slightly losing shape at speed.

Going off the Car Bible it turns out the way I have is normal for wheels that are on the wide side and on the rear of the car.

[SebringMan]

GreenV8S said:

It may be that what you're seeing isn't the tyre circumference increasing, but the lower pressure giving a longer contact patch with more slip at the leading and trailing edges which would lead to wear in the center. (I suspect it's also that longer contact patch which is messing up the handling as you describe.)

Just to bring this back .

When I checked my M3 with the Falkens on the rear and 35PSi in them (book figures basically) there was still a gap between the centre of the tyre and the ruler. So the circumference did indeed increase it seems.

I've since put on some Michelins on the rear. On other cars they seem to wear very well, not just for longevity but also the wear pattern. They seem to last too.

[SebringMan]

E-bmw said:

Not quite sure what you mean here, but surely if you put a ruler across the tread at "correct pressures" then the pressure is too low, maybe I am misunderstanding what you mean by "circumference did increase" not sure.

What I meant to say was that with the centre of the tyre worn out more I would have expected the tyre to be "straight" with a straight ruler put across them, and not to have a gap in between the centre of the tyre and the ruler.

But, going by the wear that was occurring the above made no sense unless the tyre was 'balooning' as the "Tyre Bible" suggested and would go with Helix's suggestion.