Do think its alot?

I converted my Marlin from carb to Cutler Injection syystem with a 2000 Holley Dominator throttle body and my fuel comsumtion was almost cut in half. 509 dynoed at 575HP. Then I switched to 540's with 630HP from 420's in the 39 Scorpion and in the change converted from carbs to Haltec fuel injection and again the fuel comsumption was cut almost in half. I don't know what the change would be on stock engines but it would have to be an improvement too.

I run an efi 500 and my buddy runs a 500 carb we both have the same boat, same speed. Fuel consumption has always been very close.

I get 1.2 mpg all day long with my 500 efi's in the Gladiator