Have to check on that one. Don't really run at 20 knots. Mine seems to cruise best in the 3300 to 3400 range, when it is not too rough, yielding around 24+ knots and IIRC use about 13 GPH. 20 knots is a bit sluugish for me, running 3300 makes the boat feel really good. Hull up out on top of the...