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#78958 - 03/09/03 02:54 PM Tire Question
Qnz360 Offline
Junior Member
Registered: 03/03/03
Posts: 15
Loc: NYC
Whats up! to all GP'z

ok I have factory sized tires on the car and according to the required tire pressure its 30psi(which I have filled them to) But for some reason the two front tires still look low not filled out. Could this be a bent rim, or some other type of problem?
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#78959 - 03/09/03 08:29 PM Re: Tire Question
Ferb Offline
Member
Registered: 07/28/02
Posts: 74
Loc: San Luis Obispo, CA
I run around 36psi with the stock RS-As and they still look a little flat. So it's not just you.

ferb!
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#78960 - 03/09/03 08:36 PM Re: Tire Question
GtpRed Offline
Member
Registered: 12/23/02
Posts: 66
Loc: MN
I learned something the one time i payed attention in science class! In the winter when it is colder out, the ait molecules move slower, therefore they bounch off your tire walls less often making it look like there is less air in the tire than their actually is. When the weahter warms up, these molecules will move faster, therefore hitting the tire walls more often and expanding the tires....SO! makes sure you dont put too much air in the tire during the winter, because this air will expand when it gets warmer and could over inflate your tire....just my 2 cent worth
_________________________
1997 Pontiac Grand Prix GTP-pretty much all stock-Street Scene Grills, hood bra, yellow painted callipers, and a great sounds system!
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#78961 - 03/10/03 09:52 AM Re: Tire Question
quark_man Offline
Member
Registered: 11/11/02
Posts: 469
Loc: Alberta
Another vital part of the tire build is the side wall. With newer shorter tires the sidewall is doing a lot of support. This means that the sidewalls are much stiffer and will look "squarish" no matter how much you might pump. Also another little hint when racing or wanting to be faster off the traffic light. Since GP's are front wheel drive in the initial time of acceleration the car's rear will dip - in a front wheel that is undesirable unlike a rear wheel drive. This can be somewhat allevited if you overpressurize the rears a bit, and underpressurize the front's. This leaves "room" for air expansion in the front's when they heat up....
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#78962 - 03/11/03 08:06 PM Re: Tire Question
gary Offline
Member
Registered: 08/26/02
Posts: 181
Loc: San Diego
Regarding the front tires looking a little low, an unloaded car carries much more that 50% of it's weight on the front tires. The engine and transmission plus half the car are carried by the front tires. The rear tires only carry the other half the car.

If it's always just you or you and a passenger in the car, no one in the back seat, and no luggage, run the front tires at 36 psi and the back tires at 34 psi. This'll keep things in balance, and give you the best tire wear.

Regarding cold vs hot weather, your tires are always losing pressure, so you need to keep them correctly pressurized by checking them at least every two months. Don't worry about putting too much air in during the winter, it'll leak away as the weather warms.

Regards, Gary in Sandy Eggo
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#78963 - 03/13/03 04:59 PM Re: Tire Question
Qnz360 Offline
Junior Member
Registered: 03/03/03
Posts: 15
Loc: NYC
Thanx to all who responded.
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