rgatijnet1 wrote:
The cubic feet of air remains the same with the tire, inflated or not, only the pressure changes.
Now, if you want to know how many cubic feet of air must run through an air compressor to inflate the tire to 70 psi, that is an entirely different question.
True. (Let's ignore any stretching of the tire, OK?)
To help with the second part, the density of air at 0 psi (gauge pressure) and 70°F is .075 lb/ft³, and at 70 psi is .432 lb/ft³.
All you have to do is figure out the volume of the tire in cubic feet.
