how much do you put in??? - The Unofficial BMW M5 Messageboard (m5board.com)

Steve Mac · 16th October 2002, 01:00

Just an interest

I was wondering what psi you guys put in your tyres

I have ///M Parallels and put in 38psi but wondering what you guys put in??

I know the reccomended but experience counts for more IMHO

?????

Steve Mac

Alan Yeung · 16th October 2002, 04:11

40 psi in my 235/45/17's

Mmm-Five · 16th October 2002, 10:24

I put 2.9 bar in the front and 3.0 bar in the rear

Or about 39 psi in the front and 41 psi in the rear.

I have played around a little by going 2 or 3 psi up and down, but didn't notice any difference that I could say was definitely pressure related rather than purely in my head (i.e. changed it so it must be better/worse, etc.).

I have noticed that lower pressures help in the wet though, whereas on a wet airfield I prefer higher pressures as it helps to slide the car round for a bit of gooning

IvanDias · 16th October 2002, 18:26

I go pretty much halfway between the loaded and unloaded figures in the dorwell plate.

I must admit I`ve played with the exact unloaded and then the exact loaded figures, and day to day use I can`t tell.

However, if the cars loaded with people, then I notice a lot of squealing from the fronts when loaded, eg accelerating around hard corners with the suspnsion compressed and the pressures are for the unloaded settings. Same bend with just me and it`s perfect, so BMW obviously put the two pressure values in for a reason.

I also noticed huge squeals from my right rear under pulling out from junctions, turned out to be a screw in the tyre deflating it to around 22psi rather than the monster 44psi odd it should have. Check your tyres regularly !! And the Oil. Water. Petrol. Belts. Spare. Lights. Brake fluid. Air Con. Door hinges. Sunroof. LOL.

Ivan.

mikek · 20th October 2002, 18:05

M5 40 PSI 235/45/17 and 255/40/17

M3 40 PSI 235/40/17

Malcolm · 23rd October 2002, 14:02

What you put in depends also on the ambient air temperature, loading and driving conditions etc., as well as your individual driving characteristics and tyre brand.

Personally -- I have Continental ContiSportContacts (great tyre for me!) and use 35psi in the front - 235/45ZR17 and 32psi in the rear - 255/40ZR17. BUT, the ambient temp where I drive is 35C++ , so as already mentioned, check tyre pressure & wear regularly, just as you do the coolant, oil, windscreen cleaner and fuel.
Also get the wheels aligned more often than just when you fit new tyres. It helps with handling and improves tread life.