I have read several threads on here about what pressure to run your tires at but they don't answer the following question or thought for me. If you fill your tire to the desired level when they are cold will this cause the tire to exceed the maximum recommended pressure when they warm up due to both friction and the outside temperature. Yesterday I took my brother to the cemetery and decided to check the tire pressure while he was finishing his cigarette. I have my tires filled to 40lbs when they are cold. The pressure in the tires was around 45lbs after a short trip. On my 1hr trip to work will the tire pressure eventually rise to over the 51lbs max pressure as stated on the sidewall? If so then would it be better to check\fill the tires to the desired level after the vehicle has been in motion for a while?

It is always best to check/fill the tires when they are cold. The tire manufacturer's specs allow for increased pressures when the tires warm up.

Unrelated and certainly off topic, but I can't help but see some irony in the brother at the cemetery smoking a cigarette.
I apologize if this comment offends, it wasn't my intention.

No offense taken. We actually went to see my grandparents since he wasn't at the funeral and has never been to their gravesite. The ironic thing was we found my parents headstone(they are still alive) and my brother just found out that they purchased a plot for him right next to theirs. So he actually stood on the spot where he will be buried someday, while he was smoking his cigarette!

Cool,

The maximum tire pressure listed on the sidewall is cold inflation temp. The pressure can increase to more than that while running.

For an article listing this see the following link at the Tire Rack.

http://www.tirerack.com/tires/tiretech/tirespecskey.jsp

GeorgiaHybrid Thanks. That was an interesting\informative read.

No problem, glad you enjoyed it. That site has a LOT of good info concerning tires and user ratings that I have used over the years.