My tpms sensor was telling me I was low on air so I set my tire pressures to 34/37 which is for cold, but living here in hot las vegas, should I have set it to something higher? I use a longacre gauge and don't go by the tpms sensor reading to set it. Should I be using higher air pressures since its currently really hot in vegas right now and if yes, what should I be setting it at? Even at night its above 90 degrees here. :\ And the nearest station with air is a few miles away so by the time I get there it does go up so I was thinking I should use a hot tire setting, but I don't know what it is since it's not listed in the manual or door jamb.

Thanks to anyone that can help. This probably sounds like a really lame question, but I have never had a car of this caliber that had technology like this. My former sports cars (nsx, and supra turbo) never had this tpms technology.

 

Set it at 34/37 at 68F. If a different cold temp adjust according to the table below.



Example: If the cold adjusting temp is 80F add 1PSI - 35/38.

 

Thanks, I wish it would hit 80 degrees here. I'd have to wake up at 5 am to see that temp.

 

ADias,

Thanks for posting the chart.

 

I uploaded it to my evernote account so I'll always have it ready on my phone.

 

You would want to set the pressures lower since the ambient temperature will contribute to the tires heating up to reach optimum pressure. In the cold, you would want to raise the pressures, as they take are more resistant to heating up/rising in pressure).

 

For a light load and any type of spirited driving go with the 34/37psi. Adjust the pressure cold....like at night or before you go to drive and the car has been sitting out of the sun. Also keepmin mind that when the car sits out in the sun and it shines on 1 tire and the other tires are in the shade your psi will show higher on the tire in the sun.

 

Mike,

Have you ever looked into the Longacre pressure gauge with temperature compensation? It looks interesting.

 

Lets say I go to fill up a tire at the gas station at night, but its still 100 degrees but not in direct sunlight. Do I still set it at 34/37?

 

No! You set them 2.7PSI higher (36.7/39.7). Make sure that you do this with your car engine cold as the 911 engine contributes to the temp of the rear tires.

P.S. - Many will disagree, but this is what is correct; just check the Owners Manual for 997.2 and newer where PAG clearly pegs cold temp pressure to an absolute reference - 20C/68F. Set this way, second gen PTMS will be spot on no matter the ambient temp. The Longacre pressure gauge with temperature compensation does exactly that, when used correctly.

 

Go get a small air compressor that you can use at one to put air in. Then you can use the chart ADias posted. Once you drive the car the readings won't count because the tires get warm and the pressure increases.

I bought a cheap one at the hardware store. It works great for putting in a pound here or there.

 

so which would that be, set them lower, or set them higher...kinda covers everything there...

 

I was looking at some on lowes and home depots website. Most of the small ones had bad ratings but I think thats because they use it for other purposes and use it more often as opposed to just filling up a little bit of air in each tire. I'll check into it again.

 

Thanks. I got a longacre gauge but its the regular one. The one with compensation is too expensive. If I tracked the car regularly then I would see it as something that is necessary, but not for someone like me that might only do 2 track weekends all year.

 

No no no you don't change the tire pressure depending on the outside temps.....34/37 COLD and leave it there. The chart is only showing you due to outside temps how the tire pressure will fluctuate.

You should check you tire pressure every week or so to make sure it's good.