[tomgwuyn]

I am confused on how much air pressure to keep on front and rear tyres on my 06 330i. The recommended pressure is 32 psi on front and 36 on rear. However , while driving,i feel that it is too low . Is it safe to maintain 40 on all four tyres? Will it cause any problems? Note : The rear two tyres are larger in size (255) than the front two(225). Suggestions please . I have bridgestone driveguard on front 2. and one michelin and one bridgeston driveguard in the rear.

[Welcome to NBA Jam]

Read the tire sidewall. That's the absolute maximum cold inflation pressure it can do.

[Antetokounmpo]

you shouldn't be able to tell a difference between those pressures on a runflat. they're always hard as a rock.

[max_330i]

dude, 40 psi all around in run flats? You'll be missing teeth by the time you pull into the parking lot. They'll beat you up regardless but I think you should stick to the factory 32 front / 36 rear cold. That psi will protect the wheel adequately and not cause the car to ride so hard. Ditch run flats next time you need tires...

[N52UNED]

Originally Posted by tomgwuyn

I am confused on how much air pressure to keep on front and rear tyres on my 06 330i. The recommended pressure is 32 psi on front and 36 on rear. However , while driving,i feel that it is too low . Is it safe to maintain 40 on all four tyres? Will it cause any problems? Note : The rear two tyres are larger in size (255) than the front two(225). Suggestions please . I have bridgestone driveguard on front 2. and one michelin and one bridgeston driveguard in the rear.

When you state "feel" do you mean what you think/feel they should be ... OR ... how they actually feel to you while driving?

As mentioned ... read the sidewalls, it will state the max air pressure. Another thing to mention is that although higher air pressures may be allowable ... improper air pressure will lead to poor tire performance, as well as, poor tread wear making your tires wear faster than they are spec'd; which could leave you empty handed if the tires have a specified tread life guarantee.

It's best to follow the pressures indicated inside your driver side door. Although they may feel low they aren't. You'll get used to the feel.

[floydarogers]

Sorry, screwed up edit.

[floydarogers]

Originally Posted by N52UNED

...
It's best to follow the pressures indicated inside your driver side door. Although they may feel low they aren't. You'll get used to the feel.

++ IME, you do not want to go with anything but driver-door recommended tire pressures with low-profile tires, especially RFT's. Doing otherwise can cause very squirrely behaviour, especially tramlining on rutted roads. If you think you've got pothole explosion now, bumping the tire pressure is going to make it feel like you've changed from dynamite to RDX.