I believe it is E=PV/2 So for a tyre running at 200 kPa, you need 100 Joules for every litre of space inside the tyre. Now a portable 12 V compressor takes about 1000 seconds to pump up a tyre on a medium-sized car. You probably have to pause as these contraptions get hot, but active time is 1000 seconds. Lets say the motor is 120 W, then it used 120 kJ. Then what is efficiency of the compressor? 50% ?
- posted
11 years ago