Tire Inflation: Nitrogen vs Air

Here is the math to figure changes in pressure and volume due to changes in Temp or vise versa.
(New Temp in Rankin)x (Old pressure)/(Old Temp in Rankin)=New Pressure
P2xT1/P1xT2 if that is simpler

Exp (110*F+460)x28Psi/82*F+460)=29.44psi, Your tires were 82*F@28Psi and you warmed up to 110*F the tire by driving it you would have a 1.44Psi increase in temp.

Exp- you want a optimal tire pressure of 25psi and it is 85*F out and after your burn out you get a tire temp of 128*F what would be the starting pressure you would need to get the 25psi after the burn out for the run?
(87+460)x25/(128+460)=23.25psi
Very handy if you are into drag racing and want to get eveything down to a exact sceince or you just get board like me.