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[bimmer]

Hey, I would like to know what is the best tire pressure for 330i with sport package (18 inchers). I have 28.5 front, 35 back. Is that correct?

[Ray]

According to my door jam, BMW recommends 32F, 36R.

[RGRAY]

You should check your tire pressure about every other month.

[ntpcrew13]

Should the tire pressure be whatever is posted on the door jam regardless of what tires you have? For example i switched out my 159s for 19" CSL reps, should the tire pressure be the same setup for both my winter and summer tire setup? Thanks in advance.

[obLu]

Should the tire pressure be whatever is posted on the door jam regardless of what tires you have? For example i switched out my 159s for 19" CSL reps, should the tire pressure be the same setup for both my winter and summer tire setup? Thanks in advance.

Nah, probably not. Depends a lot on the tire really.

Use the chalk line method or pay attention to the scrub on the tread. There'll be a little triangles pointing toward the tread around your tire. The scrub/chalk line should just intersect the very tip of that triangle for the tire to be properly inflated to take advantage of all the tread.

Now, caveat. That means properly inflated for your driving style. If you're always hammering corners, you'll need to run more pressure to keep the scrub/chalk at the tip of the triangle. And if you don't corner at all you'll need to run less pressure.

I wouldn't ever run less than 32psi ... I've read a couple of places that for hydroplaning a 5psi overinflated tire is safer than a 1psi underinflated tire.

Also you'll need to adjust pressure for average rate of speed. The lower the pressure, the more heat will build up in a tire. If it's real low, and you have a very high rate of speed you risk failure. That's why the manual has two sets of pressures, under 100mph and over 100mph.

Hope that helps. Sorry, there's no definitive "right" pressure.

Me, personally I run 33/35 on the stock 18" blowtenza rft.

[Holygrail]

Bimmer and ntpcrew13:

The Psi on the door is the standard. HOWEVER, it depends on what you prefer. Do you like a softer ride? Then do less than 32psi. If you like a better handling but harder ride, then add above 32psi. For me, I over-add. I add about 35psi in the Fr and 40psi in the rear. WHY? B/c of NYC potholes. The harder the tires, the less likely you'll damage your wheels on impact.

ntpcrew13, whenever you upgrade/plus-size your wheels, always add more than the recommended #'s on the door. For example, my previous car (Acura CL Type S) came with 215/50ZR17 stock. 32psi was recommended. I plus sized it one size to a 225/40ZR18. After going through a couple dented wheels, I learned that I was supposed to add more psi according to wheel specialists, ie. 35psi. After that, I had fewer dented rims.

[Barry626]

Originally Posted by bimmer

Hey, I would like to know what is the best tire pressure for 330i with sport package (18 inchers). I have 28.5 front, 35 back. Is that correct?

Manual that came with my car Pre-Sept 06 says 29 front 36 rear.
Believe shortly later they changed it to 32 front 36 rear?

My 07 Sedan now says 32 front 38 rear.

If I were you go with 32/36

[ntpcrew13]

Originally Posted by Holygrail

Bimmer and ntpcrew13:

The Psi on the door is the standard. HOWEVER, it depends on what you prefer. Do you like a softer ride? Then do less than 32psi. If you like a better handling but harder ride, then add above 32psi. For me, I over-add. I add about 35psi in the Fr and 40psi in the rear. WHY? B/c of NYC potholes. The harder the tires, the less likely you'll damage your wheels on impact.

ntpcrew13, whenever you upgrade/plus-size your wheels, always add more than the recommended #'s on the door. For example, my previous car (Acura CL Type S) came with 215/50ZR17 stock. 32psi was recommended. I plus sized it one size to a 225/40ZR18. After going through a couple dented wheels, I learned that I was supposed to add more psi according to wheel specialists, ie. 35psi. After that, I had fewer dented rims.

Thanks for the advice holygrail!!!!