jw1977

You may have seen my post regarding my new tpms sensors that measure 5 pounds low. This forces me to run my tires(Michelin PSS) 5 pounds higher so the alarm doesn't go off.I really don't like having to do this. This means once my tires warm up i'm nearly 40(from gauge reading) pounds in the fronts and pusing 50 in the back. This can't be good can it?

LexVan

U r correct. Get the TPMS fixed.

SecretAsianMan

Too high a pressure means loss of grip and uneven tire wear.

1990nein

For me with MPSS 33/37 seems to be a good balance for the car. I can feel a slight hint of sluggishness compared to dealer settings, but the overall handling and feel of the car is significantly improved. There is also a noticeable difference in MPG as opposed to running dealer settings, I didn't bother to test numbers but it appears to be up to 20% loss in MPG running these lower pressures. MPSS has a tendency to get really greasy when you start pushing over 40 psi hot.

Anyways, you have a nice car and nice tires; set them at the pressures where you can really take advantage of them. No point in forking out $1500 for tires that you're never going to take advantage of!

As far as getting the TPMS fixed, try setting it to Partial Load in the TPMS settings. Worked for me when I was testing the fronts at 28 cold and it kept warning me to add air.

You can also consider getting your tires filled with nitrogen so that the PSI doesn't fluctuate as much.

jw1977

I have it set to partial load and if it drops below 30 pounds I get the warning. I purchased my replacement TPMS through my tire dealer, however the stock sensors were off by 3 pounds. I know the place that installed them said they had to program them, can they program at what deficit the alarm goes off at or that something that Porsche has it set at? The nitrogen idea not be a bad idea.

alexb76

TMPS is usually 2-3 PSI off, but never that much off. Are you sure your other tire gauge is accurate?

808997

I had to get change my front tires today due to a bulge in one of them. When I picked up thr car, I was surprised to see the dealer inflated my tires to 40/47.

cairo94507

The dealer or tire shops never seem to inflate to correct tire pressure - ever. First thing I do is check the torque on the lug nuts and inflate to the proper pressure upon arriving home.

jw1977

I've tried 3 gauges and they all read the same as mine. My gauge is a Longacre.

chris.hanle

I suspect the car will be bouncier, have less grip, and tires will wear in the center. Other than that not much else except a little better gas mileage. I would fix the tpms. Good luck.

Eric - Plug Guy

I'm usually setting them 7% below full spec, and set for partial load. I use the race gauge we got on the group buy some time ago for accuracy, and ADias' pressure chart to compensate for ambient temps.

You should either have it fixed, or wouldn't the 'reset to current pressures' resolve this?

If they continue to read incorrectly, replace them, they are not that costly and tires are your primary life saver. And make sure you have a high quality gauge, do not go by the readout on the car.

GSIRM3

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Macster

Not it can't. My time with my Cayman S with TPMS was very short but my memory of the TPMS was it was accurate. There was some initial trouble -- nothing major -- but a reset or a recal or something -- following the steps in the owners manual -- and afterwards the tire pressure cold measured with an accurate tire gage and the TPMS agreed and all was good.

My experience with my Boxster running the front tires overinflated was the car would exhibit a vibration like tire imbalance. Lowering the pressure back to the recommended pressure cured the vibration. I have bothered to run my Turbo tires overinflated to see what happens.

Even if there is no vibration the tires will wear in center. Grip will be compromised. The ride will be harsher and likely noisier too.

I am with the others. Get the TMPS fixed or re-calibrated or reset or whatever it is called and then run the tires inflated to the appropriate pressure based on the vehicle's load.

jw1977

What's the "reset to current pressure"? I've never seen that on mine. Mine's an 07 maybe the newer ones have that?

Minok

Having a bunch of gauges that all read the same doesn't mean any of them are reading correct. You need to compare their reading to a known, valid comparison source. Some physical phenomenon like pressure producing source that is know, by volume and density of its components, to produce a certain air pressure, or compare it to a known calibrated master gauge.