Tyre pressure for 18s

TitanTim · Post by **TitanTim** » Thu 14 Apr, 2011 21:26

Hi all,

Just wandering what tyre pressures peeps are using with 18" wheels and similar tyre sizes i.e. 225/40 fronts, 255/35 rears. When I had wheels and tyres fitted the fitter recommended 31psi fronts and 36psi rears. Does this sound about right? Im thinking it might be a tad high

Cheers,

Tim.

shantybeater · Post by **shantybeater** » Thu 14 Apr, 2011 21:32

I'm running 32psi front and back on 225/40 & 265/35 as advised by chippy

TitanTim · Post by **TitanTim** » Thu 14 Apr, 2011 21:37

shantybeater wrote:I'm running 32psi front and back on 225/40 & 265/35 as advised by chippy

Cheers Shanty, I was kinda wandering if the rears were too high. I remember the fitter saying the pressures he set for mine were standard for the 3 series

I will have a play around with the rears.

Tim.

GazHyde · Post by **GazHyde** » Thu 14 Apr, 2011 22:32

32psi or so front and rear for me too. I can't remember the exact size of my 18's but they aren't far off what your fronts are Tim.

Gary

markrnorton · Post by **markrnorton** » Fri 15 Apr, 2011 07:49

I run 30psi all round, but my spring rates are higher than normal set-up

Jonttt · Post by **Jonttt** » Fri 15 Apr, 2011 11:48

I run 32 front and 34 rear

TitanTim · Post by **TitanTim** » Fri 15 Apr, 2011 14:33

Thanks everyone

Think I will run the rears a little lower

Tim.

Justin Time · Post by **Justin Time** » Fri 15 Apr, 2011 16:16

I have to laugh at the individuals in the tyre business in town and elsewhere who have recommended that I "keep 32psi all round on standard wheels and 34psi on 17/18" rims". Standard tyre pressures are roughly 32 psi. Given that your tyres will be wider than standard (255mm width on tread surface instead of 225mm), there will be less pounds per square inch forced on the tyre surface by the car when compared with standard tyres as the load is spread over a larger surface area, resulting in lower than 32 psi pressure for wider tyres. Higher than recommended pressures will make it more likely that you will encounter some uneven wear.

I can't advise a specific pressure but at a guess 30-31 psi on 255/35/18 tyres should be enough to avoid uneven wear.