# ZHP Tire Pressure: Driver's front > Passenger Front?



## SizzlerMA (Sep 23, 2003)

Hi,

I've had my 330i ZHP about 2 weeks now, done 1500 miles, what a sweet car. I just went out and measured the tire pressures with an AccuTire digital gauge from TireRack.com, and got these readings:

Front Passenger: 30.5 psi
Front Driver: 33.5 psi
Rear Passenger: 35.5 psi
Rear Driver: 36.5 psi

I know the car is supposed to be 32 front/38 rear all around. Also bear in mind that these were "hot readings" after the car had been driven for 45 minutes, and I know I should use "cold readings" where the car has not been driven for hours.

Nonetheless, two questions:

1) Should the driver's side tires have a higher pressure to compensate for the driver's weight in a car that is usually driven solo? I can't comprehend why the driver's front is 10% higher than the passenger's front---might the dealership have done this on purpose or did the tires just lose air at a different rate?

2) Any chance the tires have been damaged at these pressures? Only had the car 2 weeks, and I'll fill the tires in the morning before I drive it . . .

Thanks!


----------



## mscoins (Oct 11, 2003)

1) Both front tires should have equal pressures.
2) Probably not but check them anyway (which is always a good thing to do once a day)


----------



## FenPhen (Jan 13, 2004)

SizzlerMA said:


> 1) Should the driver's side tires have a higher pressure to compensate for the driver's weight in a car that is usually driven solo?


No. BMW seems to pride itself on having balanced cars, to the point of putting the battery in the trunk opposite the driver (for left-hand-drive cars anyway). I don't think it'd be wise to second-guess the engineers unless you've actually measured the weight on each tire with you inside. 

And #2, no. The tires might have worn a little more than at a higher pressure, but you've only gone 1500 miles, just a small fraction of the tread life.


----------



## MicahO (Apr 19, 2004)

If those were your hot readings, you'll want to jack the pressure up quite a bit. Depending on your driving conditions and ambient temps, you'll see 4-7 lbs of pressure increase at speed. (I got to watch the pressure monitor on wifey's car all the way to FLA and back this past week - 65F/static 35/36lbs be came a 99F/75mph 42/43lbs).

With those shorty sidewalls, you'll want some more pressure to give some slight protection from road hazards.

And you'll probably find the handling to be a good bit more neutral if you bring the front tires up to nearly the pressure of the rears.


----------



## BloodRedHog (Mar 9, 2004)

I went 38f/36r but I am still experimenting.


BTW, I love my Accutire - best gauge I have ever owned.


----------

