Andreas1977
New Member
Are you sure your 17.5GPH isn't at cruise?
I have a mechanical fuel flow meter and it shows 15.5GPH on my 454 at 3500rpm. Which is similar enough to this https://www.boat-fuel-economy.com/mercury-mercruiser-3.0-181-fuel-consumption-us-gallons to where I think it's accurate. I see up over 25GPH quick if I push it over 4000rpm.
sorry yes. 17.5 is at 3800 rpm going 28 mph
What Mph are you doing at 3500...?