Yummybud924

Not sure what my tire pressure should be at, they look like they are low so I want to know what they should be at.

205/60R15 are on teh front and 215/60R15 on the back on my fuchs.

not sure if these are what the original tire sizes were for this car.

thanks.

V2Rocket

iirc stock tires were 215's all around.

iirc pressure should be 30 in the front and 36 in back, its on the inside of the gascap.

jtsporsche

dont the tires say it on the side wall? mine do

quinnfiske

The pressure on the tire sidewall is a max inflation pressure given by the manufacturer of the tire. The car manufacturer specifies what the tires should be set at on the car. It will be a somewhat lower number. I would go by what it is the owner's manual and the sticker on the car. You can add a few psi to the front and/or rear if you want a bit crisper feel.

sbyrne

And don't forget to check your pressures every 2 - 4 weeks, especially when the weather changes. We just had winter start in earnest a couple of weeks ago and when I checked one Saturday afternoon, every tire in the family fleet was 5 pounds low, and that was in the (mostly) heated garage.

alex

It depends on how you want the car to respond. I think the lower the pressure, the more grip you get, whereas high pressure is more prone to breaking loose.

67rschev

Not so much ........ The more pressure , especially true with street tires , the more the contact patch and the more the grip ....... lower the tire pressure , and you will loose grip ............ I remember running 50 psi one time at the track in my friends Cobra to make the front end stick , what a pig those cars are . We roasted that set of tires that day........ Of coarse this is not infinite , or we would all be running 120 psi .........

V2Rocket

It also depends on the surface you drive on.

In sand or dirt you'd deflate the tires a bit so they flatten out and put more surface area to the ground so you don't do roostertails all day long.

On the street you want to inflate them so the entire tread patch contacts the pavement. If you overinflate the tire will balloon in the middle and you'll be driving on a small patch in the center of the tire which will wear down quickly.

FRporscheman

I think empiredsn is right. Less pressure = more grip, to a point. More pressure = more prone to losing traction, but also feels sharper and crisper.

I can't remember the manufacturer suggested pressure off-hand, but I know they recommend the same pressure for the front and the rear.

Pcar944

I think my 944's are front 30 rear 36.

Are there any cars that are the same front and rear? None that I've ever owned.

Usually(?) the drive wheels are a little higher.

alex

Yeah I was recalling my mx days. And I don't mean low enough pressure to lose much in the way of surface contact.

And obviously these adjustments should be made within reason- don't go driving around with 20psi in your tires!

Yabo

Yeah, to a point lower pressure will improve grip but you will roll the tire more in the corners so if you are too low pressure then you end up driving in your sidewall... For the street, generally you want to find a pressure where your tires are wearing evenly. Too little and the outsides of the tire will wear faster, too much and the middle will wear faster. That said I usually run 32 all the way around as i thats what feels most comfortable handling wise to me and wears the best. At autox I usually am at 35 in the front and 32-30 in the rear.

That said, my tires are all at about 25psi right now because they are summer only tires and I've been having ot drive in multiple inches of snow until the volvo got inspected.

67rschev

Caption from " Clarks Garage "

Understeer Corrections
Front Suspension ----- Rear Suspension
Softer front springs ---- Stiffer rear springs
Thinner or no front sway bar ---- Rear sway bar or a thicker one
Raise front tire pressure ---- Lower rear tire pressure
Softer front shocks ---- Stiffer rear shocks
More negative front camber ---- More positive rear camber
Remove weight from the front ---- Add weight to the rear
More down force in the front ---- Less down force in the rear
Wider tires in the front ---- Narrower tires in the rear
More positive caster. ---- Limited slip rear differential or stiffer rear diff


Oversteer Corrections
Front Suspension ---- Rear Suspension
Stiffer front springs ---- Softer rear springs
Front sway bar or a thicker one ---- Thinner or no rear sway bar
Lower front tire pressure ---- Higher rear tire pressure
More positive front camber ---- More negative rear camber
Add weight to the front ---- Remove weight from the rear
Less down force in the front ---- More down force in the rear
Narrower tires in the front ---- Wider Tires in the rear
Stiffer front shocks ----- Softer rear shocks

P-car sticker is 32 front and 36 rear ........WHY ? ? ? So they can make sure that when we drive our car beyond our abbiliteis we hit the object with the front end first , and not the back ........ Hence the "understeer" , or for us rednecks "push" ........ Lawyers made - em do it , nothin like lawsuits from idiots back-in thier car in ........

67rschev

OOpps ...30 front and 36 rear is right ...... Was going off of memory

FRporscheman

Hmmm I usually take clarks garage to be factual but I think that is a mistake. It should be the opposite of what he has there.

My 968 gas door states 36psi for front and rear. The 944 is back in San Francisco so I can't check it, but I was certain it also said 36/36... Maybe not.

Porsches (well, these Porsches) are configured from the factory to have understeer because it's much easier for an average, novice driver to correct understeer than oversteer in a panic situation.