honestly you will be fine with that and shouldnt run out of air at all as long as your cfm on the gun is lower then the compressors .... a hvlp requires about 10-15 psi to run so 8 cfm at 40psi is plenty .... I spray my clear with a gun that takes up 9.6cfm and the compressor i use is 10cfm @ 40psi and i shoot the clear at 40-45psi and never have a problem even on a all over job....