Question: how much scfm to paint a car?
Answer: This is often given at air-pressure levels of 40 pounds per square inch (PSI) and at 90 psi. A regular siphon-feed spray gun requires 6 to 8 scfm at 40 psi, while many air tools, such as sanders, can require 6 to 8 scfm at 90 psi.