This spring, I got Star Specs. I've had them about 5000 miles. I had 34 psi in the tires warm (normal driving) the day I got them right before the alignment.

I got the TPMS light on my HUD today after work in mid 40s weather, thought I had a low tire. I pulled off at a gas station to check them with my gauge. it turns out all four of them were down to 26psi cold. I didn't have any quarters on me, so I headed home. I drove about 5 miles on the highway at 80mph, and they warmed, hit 29psi (checked at home), and the light went out.

I snagged some quarters from my daughter's piggybank and kicked them back to 35psi warm.

Cliff's notes: Check your tire pressure if it is cold where you are so the TPMS light doesn't come on one afternoon and take your HUD hostage.

The end.

 

You stole your daughters quarters from her piggy bank?

Moral of the story... you are a very very bad man.

 

Happened to me recently too. When the weather changed and got much colder recently... I got a TPMS warning as all tires went down in air pressure.

 

Or you could fill the tires with nitrogen. Less deviation with ambient air temp changes, also less moisture.

 

1 psi drop per 10 degree F? my tires dropped from 36 to 31 and it is only 55F

 

Where you think she got all those quarters, mang? I empty my pockets when I get home, she friggin' grabs my change and sprints down the hall. Its like Halloween Candy Tax. My car needs love, she can give back a dollar to the Evo.

 

Exact same thing happen to me, my BFG's were down to 25psi. Didn't realize how much psi is lost in cold weather and it wad only 55-60 degrees when it happened.

 

Yep... Last winter the same happened to me last winter... Only that in my case "I HAD QUARTERS" and didn't took em from my daughter... <- says; shame on you if you haven't returned the funds back with 20% interest, and another 30% for emergency needs, plus another 15% for not asking permission, and breaking the everything daddy has in his pockets that jingles is mine rule.

 

Its ~1psi per 10F change. If you set them at 34 psi in say 80F (summer), plus some loss overtime from air sneaking out, you can get 4 psi from temperature change and 4-6 more from loss. Nitrogen filling is an option. The molecules are larger, making it harder for them to escape.

Tire psi is best set cold. Its also worth noting that some extreme tire compounds (silica compounds - Z1*, RE11, A046, etc) do not like temperatures below 40F. There could be a severe loss of traction at those temperatures.

Another factoid, gas mileage can be affected by 0.3% for every 1 psi drop below spec.

 

check/set tire pressures "cold" not warm.

before car is driven or and hour or so after being driven.

 

P*v = n*r*t

 

everyone listen to this guy^^^, he's a scientist.

 

lol

 

Havent had that happen just yet in the Evoslow. My vette does the same thing... but normally after a couple of minutes of driving it heats them back up.