Why different pressures front and rear?
- Thread starter aimatdeer
- Start date
the rear will be carrying more weight than the front (when loaded)
Nose-heavy pigs of cars require usually considerably higher tire pressure in the front. Vehicles around 50/50 weight distribution have identical or very similar front and rear pressure. Load (driver, passengers, cargo)) commands an adjustment in tire pressure and this is reflected by the label that is either inside the gas flap or on the door jamb. In trucks the load is of course an even more important factor.
May also be a handling issue, little lower in front as rear end is lighter and they would rather have more understeer than oversteer as that for most drivers is more predictable.
I've seen 30/35 in BMWs.
It's supposed to have near 50/50 distribution.
It's supposed to have near 50/50 distribution.
with just driver or loaded? can't be both.
yes.
Apparently it's about a 60/40 ratio between front and rear weight.
seems normal for a FWD based car
Staggered tire sizes in this case?
Multiple factors can affect how the factory specifies tires pressures. Front to back weight distribution and load carrying as has been mentioned. The amount of over or under steer due to roll centers, camber curves, etc. can be compensated for to some degree with tire pressure. Ride quality is another big factor.
No four wheel drive
My 2008 3/4 to Suburban says 50 psi in the front and 60 psi in the back with load range E LT tires.
The BMW mentioned has four wheel drive?
This is in a RWD E46 with same tire size.
The owners manual also tells you not to rotate tires.
My 328 specified 32 psi front and rear, I ran 35 psi. The recommendation to not rotate is common for BMW. Regardless of the cehicle, I have only ever rotated from front to rear and vice cersa. Can't remember using non-directional tires on anything other than my Rabbit.
