I don't know about doing the math - but - My Stover CT-1 (2 HP) has 45 psi My Jaeger 2½ HP "S" has 50 psi Joe "Pip" Betz said that. jlb94 at juno.com - - - www.oldengine.org/members/betz ,-._,-. "There is nothing like sealing a letter \/)"(\/ to inspire a fresh thought". (_o_) http://community.webshots.com/user/pipbetz