Fuel Consumption on a 1990 9.9 Johnson

[esteban14]

Hello all. New boat owner here. Well, I say boat, but it is actually a 16ft inflatable so hopefully I won't be shunned. Plan to take it out into the 10,000 Islands of So Florida and need to understand fuel consumption. My short web research has yielded the following rule of thumb HP/10 for GPH at WOT. Therefore I should get something a little better than 1 gallon per hour. #1 does that sound about right for my motor and #2, at 3/4 WOT, what ballpark MPH will I be doing. I realize there is alot of variables but I am just looking for a range so I can plan how much fuel I will need for a weekend trip. Thanks in advance for your patience and comments.

[Will Bark]

I would still calculate the 1 gallon per hour and not telling what speed you would be going; depends on boat and load being carried. What ever you come up with I would double that figure; better to bring some back than run out. Good luck and have fun.

[raczekp1]

i run my 9.9 for 6 hours on troling speed,with 2 person and boat 4m long, weight 100kg and i lost 5L (1.5 galon) of fuel

[esteban14]

i run my 9.9 for 6 hours on troling speed,with 2 person and boat 4m long, weight 100kg and i lost 5L (1.5 galon) of fuel

Thx racz. Any idea what you would burn at 3/4 WOT? Does 4L per hour sound reasonable?

[raczekp1]

at 3/4 i think you will burn 2-3L per 1 hour