Whenever the question about recommended tire pressure comes up, one recommendation is to go by what it says on the door jamb. In my case (2006 MCS) that number is 30 pounds. Sounds like reasonable advice.

But isn't this factory recommendation based on runflat tires for the Cooper S? Now that I've switched to non-runflats, I wonder if this same number still applies as a good recommendation.

Since runflats are a different compound, I wonder if this amount should be adjusted (up or down?) for non-runflats.

Any ideas?

Thanks!

 

My quick guess is that it does apply to non-runflats. Regardless of which tire is on, either one will eventually collapse (even the runflats after enough miles) without enough air pressure. The air pressure is what keeps the tires' shape and supports the car, and the recommended air pressure is appropriate for the expected weight of the car. That's my best educated guess.

 

The tire pressure on every car as shown on the label on the door jam applies to that car not to the tires being used.

Your owners manual will also show the tire pressures recommended.

While you can inflate the tires a few psi above the recommended levels you should not allow tire pressure to be less than marked on the door jam.

In the case of a MINI you can easily use 32- 38 psi cold. 38 psi will give the tires less rolling resistence and allow for slightly higher mpg but ride comfort will be rougher/bumpier.