I have a new '08 GT3 and I constantly get tire pressure warnings. I use my own compressor to put 29 PSI in front and 33 in the rear before I take the car out and continually get the warnings. I hand check the pressures with a good TP gauge when I fill so I know the pressures good. Any thoughts?

 

I just had a similar issue when I was tracking the car. I had the cold temps @ 28 front/29 rear. Once the tires warmed (pressures 33front/36 rear) the warning would not come on. But I had to reset the pressure at each run session. The Michelins like to run at 32-36 psi. When I finished the track event I set them @ 32 front/34 rear and no more warning. I would of thought the programing would allow the pressures to be set for a cold track pressure. I hope someone else has a way around this (other than taking the sensors out)

 

Thanks for the info I thought about allowing for the higher pressure readings once the tires heated up but I left the pressures where they were. I'm just afraid if I start out at 32/34 when the tires heat up I'll be at 34/36

 

I had the same problem at 29/33 and no problems at 30/33. Seems strange that 1 psi would make a difference but it did.

 

Thanks, I guess I'll just experiment and hopefully I'll be lucky and just go up 1PSI like you. I really think this is not an exact science and is more of a pain in the you know what. I already read that 1 of the improvements in the '09's will be the TPM system. Otherwise the car is great, I love it far more then the TT I had previously.

 

also remember the tpm primarily shows trends and may not be absolutely accurate. Make sure the guage you're using is accurate.

 

Yeah I agree, I hardly drive my TT anymore.

 

the tpms is a liar! mine seems to be off by 4psi (cold and hot). i had 3 external gauges that told me so. although it does well detecting unbalanced tire pressures. i had a slow leak from a nail on the tire and it sensed that tire was -5psi off from the others.

 

So does your system constantly show error or have you resolved your problem by adding more PSI's??

 

Indeed.

 

mine resolved by increasing the pressure. The tpm was still great on the track to show trends. I knew what my cold pressures were and could see the increase as the tires warmed. I think the tpm accurately registers the increase (or decrease if a tire is going down), but can't deal with the correct cold temperatures for track time. On the setting sequence there should also be a "track" option in addition to the summer/winter tire option. That's what these cars excell at!

 

I agree it's not very accurate but if you set it for a minimum of 30F/33R after measuring it with a good tire guage (I use a longacre) it works for seeing if 1 or more tires is losing pressure and I like knowing how much the pressures are increasing after some hard driving since these tires don't have great grip when they're cold.

 

^^^ yes it's good to know how much the pressures are changing from cold to hot. i just don't rely on it for actual pressures. like you say it's not very accurate.

 

The TPMS in my car STINKS! It's totally inaccurate and annoying.

 

It's not accurate but useful for the reasons i stated above.