Not in my experience with my Perkins. 6.7-6.9 knots cruise, no-current at about 1.8 gallons per hour. 8.0 knots max after a while. MPH maybe. After 6.9, the wake just gets bigger and you burn more fuel for every 0.1 knot/ 100 RPM.Was looking at a mid 80's Monk designed MMC 36ft single Perkins. Very clean. Broker clammed cruising speed 8 knots. Max 10 knots. Does this sound right?