I have a year 2000 Johnson 200 HP outboard on my 89 204 c and at 3500 rpm I'm burning between 8.5 and 10 gph, according to my Northstar fuel fl,ow meter. The variation depends on weight, wind, waves, tide, etc. I average about 2.7 mpg at this rpm range on down to about 2 at wot, about 5800...