those who run mercury 2.4 and 2.0 motors ...

[Airslot]

I'm running a 2.0 l 1988 150 on a 20' V-20 Cuddy. I have a 17p Rev 4 that turns 5600 top end. I top out around 42 mph with the prop, but cruise around 26 mph at 7 ish gph @ 4000 rpm. Under most all cruising conditions I can get 3.3 - 3.5 mpg going by flow meter. If plowing through the rough offshore it can drop to around 2.8 with tabs down. Mine has been excellent to me.

I have no experience with the 2.4 l motors, and can confirm the 2.5's are quite thirsty...