Tyre Psi

[SIXPACKDREAMER]

Hi.

I have just upgraded my E34 wheels from 225/60/15 to 235/45/17,
and i am not sure what psi I should have the tyres.
Can someone give me some advice.
Cheers.

[molesz]

I have same tyres 235/45/17 and I drive them at 2.5 bar all 4 (dunno how much psi is that) and everything is just fine.

[AllanS]

that would be 37 psi

[molesz]

Allthough on a newer BMW door-hinge-sticker you can find some data about tyre preassures for exactly these tyres (it is 2,1bar front and 2,5 rear wheel for lightly loaded wehicle and 2,5 front and 3,0bar for fully loaded wehicle with M+S tyres / 1,9bar front 2,3bar rear for lightly loaded and 2,3bar front and 2,8bar for fully loaded wehicle with summer tyres), I have tryed these preassures but suffered some deflations on rough roads, specially at cold weather ... so I stick to 2.5bar cold tyres all four wheels, and have no problem since. (Just for the record I have german Borbet alloy rims).