I've neglected to check my tire pressure so I did it this morning. It was freeezing, temp barely hitting 50. I understand that the sticker behind the door says 32 PSI for cold tires. But is that when it's warm outside? Remembering my 3rd grade science, cold air contracts since molecules don't move much. Therefore, should I inflate to 32 or stop at around 30 since it'll climb to 32 when I roll for about a mile or two?

 

Ideally you'd want the same pressure regardless of temp. As it gets colder your PSI may drop some and you'll have to add air but your goal is to have the same pressure in the tire at all times, not the same quantity of air.

 

Cold pressure is based on the ambient air temperature your driving in.
You want to set your pressures before driving.

The vehicle needs to be stationary for at least 4 hours prior to this. I prefer to do in 1st thing in the morning.

Make sure your tires have not been sitting in the sun 1st thing in the morning, it can alter pressure.

A rule of thumb is you'll loose 1 psi for every 10 degrees of ambient air temperature change . You also loose on average 1 psi a month just from heat cycles. Its a good idea to check monthly @ minimum.

Alex

 

It's gonna be in the 50's here in Chicago today, and I'll probably be wearing shorts and a t-shirt when I go for a run later...

 

I had the same thoughts. I'm looking forward to the 50º weather this weekend - I'm going biking

 

50 is freezing? Maybe for some but in Hawaii it's time for a jacket if it's in the 50s.

Follow what Alex recommends is best. Check tire pressure and don't be afraid of cold pressures about 34 or 35. If it stays really cold then a little higher is also fine.

If it really warms up then check pressure again if needed. Most owners don't check pressures enough and often will run low. A little high is better than too low. Sunlight does heat up the tires so checking early in the morning is a good practice.

 

Hey, where I live, summers average over 105 with little rainfall. Worse, it's better if it doesn't rain because a quick storm only makes it extremely humid. At least you don't have to live in a place where the temperatures change on a very wide scale. It could snow (yep, it did about a month and a half ago). Even then, I don't forget heat waves overnight, you know! I don't have a good immune system and it's VERY easy for me to catch a cold. If I catch a cold, it seems like 99% of the people around me are in better health than me. I even get sick indoors when they crank down the a/c in shopping malls in the summer.