Tire pressure question - 986 Forum - The Community for Porsche Boxster & Cayman Owners

bmarti13 · 02-09-2013, 08:03 PM

Hey guys,

I bought an 03 S with Michelin pilot Super Sports. The front tires are at 25 PSI and the rears are at 35 PSI. Is this right? I am not doing any track time, just spirited road and highway.

Thanks for the advice

teleski · 02-09-2013, 08:43 PM

No. Porsche spec is 29 front 36 rear. I just put on a set of Pilot Super Sports, 18", and prefer just a little more pressure in front, 30-31, to lighten the steering on my daily commute. 36 on the rears feels right to me.

bmarti13 · 02-09-2013, 09:12 PM

Thanks! I'll adjust tire pressure tomorrow.

Joe B · 02-10-2013, 04:08 PM

If you forget, pressures are listed on a sticker inside the gas fill cover. I run 30F/35R on my 2003 s, but as teleski said (how's the skiing?), 29/36 is the factory recommendation.

san rensho · 02-10-2013, 07:03 PM

Go with the same tire pressure on all tires, 32-36. The 29 front pressure is to induce understeer, which exactly what you want to get rid of in a Boxster.

RoadsideStig · 02-10-2013, 07:13 PM

As Joe B said check on the sticker inside the gas fill cover assuming you want to do run the recommended tire pressure! It really comes down to preference, for street use I tend to do F32 and R34, and on the track F34 R36. :-)

Porsche Chick · 02-11-2013, 07:08 AM

My '09 is 31 front, 35 back, if I remember right.
We were told to inflate all of them to 40 for an autoX, but that didn't sound good to me at all. I just added 6 lbs each. I think they were addressing the 911 owners.
You don't have the pressure label on the inside of the driver's door column?

Perfectlap · 02-11-2013, 09:55 AM

Quote:

Originally Posted by san rensho

Go with the same tire pressure on all tires, 32-36. The 29 front pressure is to induce understeer, which exactly what you want to get rid of in a Boxster.

YEP... Although to Porsche's credit, most drivers probably need understeer to keep them from getting ahead of themselves.

I run 35 all around mostly. Cuts down on the rattles too.

BYprodriver · 02-11-2013, 10:35 AM

Quote:

Originally Posted by Perfectlap

YEP... Although to Porsche's credit, most drivers probably need understeer to keep them from getting ahead of themselves.

I run 35 all around mostly. Cuts down on the rattles too.

I would love to hear your theory on how this works!

Perfectlap · 02-11-2013, 11:44 AM

maybe its just in my head. Seems like when air pressure is low (below 30 up front), I feel every seam in the highway asphalt and every pot hole on the local roads.

NoGaBiker · 02-11-2013, 12:28 PM

Quote:

Originally Posted by Perfectlap

maybe its just in my head. Seems like when air pressure is low (below 30 up front), I feel every seam in the highway asphalt and every pot hole on the local roads.

Hmmmm... should be just the opposite. Think in terms of pushing a cart across a hardwood floor or asphalt parking lot. If it has solid casters you'll feel a lot more than if it has pneumatic tires. And if the pneumatic tires are carrying 50psi, you'll feel a lot more than if they're carrying 15psi (but it will also be much easier to push.)

tonycarreon · 02-11-2013, 12:30 PM

Quote:

Originally Posted by Perfectlap

maybe its just in my head. Seems like when air pressure is low (below 30 up front), I feel every seam in the highway asphalt and every pot hole on the local roads.

+1

though i don't run the same front/rear. i prefer 34/36. running with 29 front makes me feel like i'm trying to drive a wet sponge.