Our Perkins M30 gives us approx. 0.4 gal/hr. This was calculated for 3/4 season in 2005 considering about 30 gals consumed. A 1999 that sales with us, #647, is a Yanmar 3GM and gets about the same. Warren & Pattie Updike C320, #62, 1994, "Warr De Mar" Frog Mortar Creek, Middle River Chesapeake Bay