Tires should be checked cold, but your cold may be different to mine! Just don't check them hot. It is far better to check them often than worry about the small ambient changes between days. say once a week so you can catch a deflating Tyre before you run it down a motorway and it gets overheated, de-laminates and gives you hassles. I have been running at 55 psi with no problems with speeds up to 70. but doing this is on your own head.

 

Inflated my tires the other day from 35 PSI to 40 PSI to give you a heads up with cold vs warmer weather and the readings.

40 PSI morning 74 degree ambient

41 PSI afternoon reading, 84 degree ambient

44 PSI registered when I took a short drive to the gas station 3 miles away

On the tires side walls, it says not to inflate the tires more then 44 PSI.

 

The effect of the ambient temperature on tire pressure means that pressures must be reset for the seasons (release air in the winter, add air in the summer).

At higher pressures, the pressure will increase less as you drive because the tire flexes less. One hot summer day last year, I set my tire pressures to 51psi (the sidewall rating for those tires), drove about 60 miles on the interstate, and immediately rechecked them with the same gauge. They were still at 51psi.

I suspect that the speed that you drive would also affect the temperature by affecting the rate of flexing.

 

That's the tire manufacturer's legal department's idea of maximum pressure to cover their heiny.

You'll want 100# if you want to get up on two wheels.
Driving Under Pressure (full article) - CleanMPG Forums

 

That's the tire manufacturer's legal department's idea of maximum pressure to cover their heiny.

The correct tire acronym when referring to manufacturer's recommendations is PShI – Pounds Per Square Heiny Inch.

 

"release air in the winter, add air in the summer"

Kinetic molecular theory disagrees. Basically, pressure and volume are directly proportional to temperature and inversely proportional to each other. You will need to add air in colder weather to retain a given pressure. Fact is tires are constantly bleeding air slowly and need to be checked regularly and topped up. A good dial gauge is more accurate than a pencil type.

 

OOPS, sorry, I got it backwards!

 

I worked as a service man in a garage when I was in college (...while ago... issshh). We had this nice lady that came in asking "Do you sell summer air for tire ? My husband asked me to come here a have you put summer air in my tires. Can you do it and how much does it cost ?" We had a major group meeting wondering "Do we tell her or not...". Years after, this is still the running gag with friends...

:rotflmao: :Laughing Sign:

 

uhhh, I wonder if hubby did not really say 'put some more air' vice 'summer'?

Sorta like how some people think the lyrics of a song are different than what was written?

Naaaw......I like SUMMER AIR better...

 

Any of you prefer 'dry air' or nitrogen?