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Discussion Starter · #1 ·
for a set of 18" wheels (M Parallels) with Dunlop SP Sport 8000 tires.

Front 235x40x18
Rear 265x35x18

The chart on the driver's door doesn't list 18" sizes in my vehicle. That is probably 'cos these are M5 sizes!
 

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Go Mountaineers!
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I run 36 F and 39 R on mine. I have the same setup as you except I'm using Kumho ASXs.

Mike
 

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Discussion Starter · #3 ·
Driver8 said:
I run 36 F and 39 R on mine. I have the same setup as you except I'm using Kumho ASXs.

Mike
I set my fronts to 36, and the tire almost looks flat, especially when turned side ways! :dunno: The tire shop says it should be set to 40psi, but it says right on the tire 40psi is the max recommended. Don't know if it's wise to leave it that high...possibility of blowing the tire!
 

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Tire pressure is largely subjective but it also depends on a number of factors:

(1) Load (is it just you in the car...do you often carry passengers...lottsa gold in the trunk? :) )
(2) Tire itself (what does the manufacturer recommend)
(3) Your driving habits--I'd start with what either the tire maker suggest or BMW suggest and then adjust it up or down (maybe 5 psi either way?) and see what you think.
 

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I wanna DRIVE!
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Some thoughts

I just did a bunch of research on this same topic. I have 235/45 17s on the front and 255/40 17s on the rear. In sum, I started off at 38 psi all around and after a week or so changed to 36 psi in the front; 38 rear. As Agent 99 notes, there is a distinct personal element to this, so you have to experiment yourself.

I was told that the recommended pressures on the door frame are too high because BMWNA was concerned that we would not increase tire pressures when loading up our vehicles. Thus, we are being told to inflate our tires for a full vehicle even though that may not be how we use it. I drive my vehicle alone most of the time, so I went with lower tire pressures.
 
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