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jeffbco said:
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911freak said:
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ADias said:
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911freak said:
I checked the tire pressures today, the manual says the Carrera S should have 44 PSI in the rear tires and 37 PSI in the front. All four tires were at 34PSI from the dealer, what were they thinking? I guess they weren't. After I did this I then manually reset the TPC system and now it works beautifully. Thanks for all the advice from everyone.
The 997 Carrera S should be set at 33PSI front, 39PSI rear (with up to 2 people). 36/44 is for max load and is way too high otherwise. See your manual pg. 334.
Thanks for the info. Pressures have been set accordingly, though now i find myself wondering how accurate the wheel's TP sensors actually are. I have what I think is a fairly accurate digital tire gauge that reads to within a half pound of pressure. I set pressures with it, but then the cars own TP sensors say each tire is 3 pounds lower than what my gauge says. I am not sure which is the more accurate, so I compromised by adding 1.5 pounds per each tire
Some report that TPMS and manual gauge readings are the same. My experience is that TPMS reads 4 psi higher on all 4 wheels so that's how I adjust. I depend on TPMS to tell me if I have a leak while driving but I always check the pressures with a manual gauge before driving.
It really doesn't come across in the copy of the driver's manual you attached above, but you are not meant to adjust the tire pressures using the "normal" pressure display readings which you can call up when you are driving the car. Those readings show the "actual" pressures without any compensation for temeperature variations.
Tire pressures should be adjusted using the so-called "pressure info" display, which can only be called up when the car is stationary. This display shows variations from the recommended values as + or - values either side the datum, and the readings are temperature-compensated to correct values to the equivalent of 20* Celsius (=68* F).
That is, the objective when adjusting tire pressures should be to get all four wheels' readouts to "0" by adding or bleeding off air accordingly.
