Tyre pressures

[Rockhopper]

I’ve been running my rear tyres at 32 psi but I’ve noticed that they are significantly more worn in the centre than at the edges indicating that they are over inflated. A lot of people seem to run their tyres at higher pressures than this so do you sacrifice tyre wear for handling or should they actually be run at much lower pressures than people think to even out the wear? Is it tyre make dependant or will all tyres of the same size wear the same way?

 

[Chris_D]

Where do you get the idea that 'a lot of people seem to run their tyres at higher pressures' ?
I would suggest most people actually inflate their tyres to the correct spec as indicated on the label in the door jamb.

 

[Rockhopper]

That’s entirely not true as those pressures are for the run flat tyres which are fitted as standard. There are not many owners still using run flats.
According to the sticker my rears should be at 36 psi which is way too high for non run flat tyres and would make the uneven wear even worse.

 

[Bob123]

That’s entirely not true as those pressures are for the run flat tyres which are fitted as standard. There are not many owners still using run flats.
According to the sticker my rears should be at 36 psi which is way too high for non run flat tyres and would make the uneven wear even worse.

The label on my door jamb only has measurements in metric (bar) and doesn't specify for what type of tyre, or even if there is a different requirement for none runflats. I seem to recall that the M versions of our cars were supplied without runflats and with this in mind I'm wondering if any M car owners could let us know what the sticker says on their car? There may also be differences between roadster and coupe as I would have thought that the coupe was heavier, differences between none facelift and facelift and of course engine type?

 

[enuff_zed]

The make of tyre can make a difference. I've found some wear more in the middle than others, which I can only put down to centrifugal force pushing the centre of the tyre out at speed.
Worst ones I ever had, admittedly a long while ago, were Goodyear NCTs. Once worn, parked on a flat surface you could almost see daylight under the centre of the tread, but with 4-5mm left on the edges.
I suspect it'll come down to experimentation, balancing handling against wear until you find what suits you, your driving style and the type of driving best.

 

[grannyknot]

I seem to recall that the M versions of our cars were supplied without runflats and with this in mind I'm wondering if any M car owners could let us know what the sticker says on their car?

30 front, 32 rear. I'm not sure if NA cars came with runflats, I have performance summer tires and those pressures work for me.

 

[patriot66]

Rockhopper, assuming you're on staggered 18" wheels with 225/40 front and 255/35 rear ? If so then try 2.1bar/30.45psi front and 2.3bar/33.35psi rear in your non-runflats. These are the standard runflat pressures from the door jamb placard. I've been using these pressures in various non-runflats over the last 8 years and never suffered any un-even wear except the usual inside shoulder wear from camber. Depending on the tyre itself and road temperatures/conditions you can always adjust the pressure up or down if required