Hi - I have a 2008 550i sport with the style 172 19" wheels. The door sticker says to inflate the front tires to 35 and the rears to 39. I rarely have passengers or cargo in the car. I have read others posting that high pressure can lead to cracked rims.

I was curious what psi others are inflating to, and what would be the best in my situation.

Thanks for the help.

 

Also, the roads in my city are absolutely horrible.

 

In all my years of owning BMW's I inflate the tires with the psi that is listed on the door sticker and I've never had a tire or rim problem. Good luck
cheers
vern

 

I also use the recommended door pressure for my 535i (32 front; 36 rear) with 17" 244 rims. I have had one tire develop a golf-ball sized lump on the side wall (replaced) but no rim problems. Personally I believe soft tires can cause rim damage because the tire will depress enough that the rim will be hit in the event of a pothole confrontation. A tire too hard makes for a rougher ride and potential rim damage since the tire won't depress at all and all of the force from a pothole hit will be tranferred to the rim. My $.02.

 

The door sticker has a single pressure value for front and rear. If you look in your owner's manual, you'll no doubt find a range of pressures that are suitable depending on load and maximum anticipated speed. For my 2010 535i M-sport, with 245/40 R18 all around, the range is from 32F/35R with up to 4 passengers (good to 160) to 38F/45R with 5 passengers plus luggage at up to 160 mph. A full load limited to 100 mph requires at least 32F/38R. The ride can be really punishing at the high pressures while at low to moderate speeds but smooths out once you get going.

I had one wheel bent already running 38 lbs in the rear with the runflats. I just replaced the runflats with Continental DWS all seasons. Its almost ghostly quiet now; the road noise is gone except on really bad surface. The improvement in ride was not as great as I had hoped.

 

i have 235/40 265/35 and I run them all @ 41 cold. You wanna run the tire in its load range to handle the weight of the car and also @ 41psi gas milage improves slightly.

 

I often wondered how the door tag correlates with the pressure stated on the tire itself. The car manufacturer can't possibly know the myriad of tire and rim choices that people have, so wouldn't the tire manufacturer be a better guide?

 

Pressure on the tire wall is the maximum that the manufacturer recommends, beyond that pressure they do not 'warranty' failure.