2000 Boxster Tire Pressure

[Commander]

Just installed Continental Extreme Contact Sport Plus Tires on 17" Rims. My prior Bridgestone's were set to 29F and 36R pressure per the owner's manual. The Tech set the new tires at 34 F and R. The car is 20 years old and maybe there is a reason for the change in pressure. The car handles fine with the 34# pressure but not not driving hard during the recommended break in period. Any recommendations from those who have been driving their Boxsters. Thanks!

[BYprodriver]

I would just drive it like that for a while and closely monitor tread wear. Lower air pressure to suit your preference for ride comfort &/or cornering gradually.

Having said that,I have known some great mechanics that know nothing about tires! I run 34 F & 35 R in my 2000 Box

[Qingdao]

35 psi is industry standard for new tire installs. Put them at the pressure you want for the driving you're gonna do. I run factory spec pressures on my boxcars. If I was to hit the track or something I suppose I'd lower them a lot. Highway driving raise them up.

[Racer Boy]

You probably won't notice much difference in regular street driving. Porsche wanted the car to understeer so the average driver wouldn't spin the car, so they specified low pressure in the front tires.

[Riggsbie]

I tried F29 R34 (Michelin Pilot Sports) for some fast driving in twisties, and it really improved my MY99 2.7... previously I was running F34 R36

[Qingdao]

Originally Posted by Racer Boy

You probably won't notice much difference in regular street driving. Porsche wanted the car to understeer so the average driver wouldn't spin the car, so they specified low pressure in the front tires.

I thought dropping pressure in the front would give the tire more grab and decrease understeer?

[Racer Boy]

Originally Posted by Qingdao

I thought dropping pressure in the front would give the tire more grab and decrease understeer?

Nope. At least not with street tires, with less pressure they roll over on the rim and you only use the outside edge of the tire, giving less grip. That equals understeer, which for most drivers is much safer. The Boxster from the factory came with little to no negative camber for this reason.

However, Porsche did build into the car the ability to change camber a bit. Not as much as some of us would like (those who track the car), but it's enough to make a sizeable difference.