I have a 2003 325i with leather, HK, 5 speed, and sport package with 225/45/17 tires. The manual says optimum tire pressure is 35 psi back and 30 psi front. It seems very strange to have such a difference between front and back. Also, when I pressure them this way, the back end seems very "bouncy". Any advice from anyone as to how you pressurize yours?
Tire Pressure
- Thread starter jstiebe
- Start date
They recommend the different pressures because our cars are rear wheel drive. The rears are stressed a lot harder under hard acceleration so........higher pressure in them will help the car's overall handling.
If you don't do any spirited driving then it probably doesn't matter much that if you fill the rears more.
If you don't do any spirited driving then it probably doesn't matter much that if you fill the rears more.
I disagree, I strongly believe the tire pressure listed by the manufacturer is a starting point. My best footprint isn't 30 psi in the front and 35 in the rear. I have found 28.5 psi in the front and 30.5 in the rear. I have new tires and using the manufacturers recommendations was resulting in premature wear down the center treads of all four tires, which indicated over inflation. I run a chalk line across the thread and roll the tires a few revolutions and check for even wear, then inflate or deflate to adjust and start the process all over again until I'm satisfied. I get much improved tread life, plus I know I have the best foot print for traction and stability. This usually causes a small loss in mpg, but hey - lifes full of trade off's! [read]
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Michelin like any other tire manufacturer doesn't know the application your using there products on, so they give you max tire pressure for safety reasons. BMW recommends pressure for normal and heavy loads but again for the most part it's safety reasons. Think about what I have heard on this board relating to tire rotations, some people are saying BWM doesn't recommend any due to a number of reasons. I personally think tire rotations area a good thing and if you have vibration problems because you rotated and balanced your wheels, you need to look into the cause. Heck even tire manufacturers recommend tire rotations, don't you think if they could they wouldn't, they could plan on making twice what there making now just in replacement services alone. But that's another story...After thinking hard on something, common sense wins out every time.
I contacted BMW of North America and asked about tire pressure recommendations on the drivers side door panel and this is the reply I was given.
Dear Mr. Porter:
Thank you for contacting BMW of North America, LLC regarding tire pressure
recommendations. The recommendations on the door panel are just that,
recommendations. It is not a requirement. The recommendation is based on
averages such as number of passengers and cargo, driving speed, environment,
etc. You can adjust the tire pressure accordingly. For the best results,
performance and safety related, you should check the tire pressure and tire wear
often, and adjust for any significant changes in normal use. (i.e. loading the
car down with passengers and luggage for a long vacation)
If you have any further questions, please respond to this e-mail or contact the
Customer Relations and Services Department at 1-800-831-1117, Monday through
Friday from 9:00 A.M. to 9:00 P.M., Eastern Standard Time. Again, thank you for
contacting BMW.
Sincerely,
Anthony Salla
Customer Relations and Services
Representative
Dear Mr. Porter:
Thank you for contacting BMW of North America, LLC regarding tire pressure
recommendations. The recommendations on the door panel are just that,
recommendations. It is not a requirement. The recommendation is based on
averages such as number of passengers and cargo, driving speed, environment,
etc. You can adjust the tire pressure accordingly. For the best results,
performance and safety related, you should check the tire pressure and tire wear
often, and adjust for any significant changes in normal use. (i.e. loading the
car down with passengers and luggage for a long vacation)
If you have any further questions, please respond to this e-mail or contact the
Customer Relations and Services Department at 1-800-831-1117, Monday through
Friday from 9:00 A.M. to 9:00 P.M., Eastern Standard Time. Again, thank you for
contacting BMW.
Sincerely,
Anthony Salla
Customer Relations and Services
Representative