I said I knew there is a simple formula. That doesn't mean I know it.
But, I bet there are a few guys on this forum that do.
I saw discussions on
www.autobodystore.com and I believe estimates for 5hp compressors were in the 3 hp range. The easiest way to find out is to read the metal plate on the motor itself. They try to hide the true reading but apparently it is decipherable and can be figured out using some formula.
