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Good Morning,

I have been a bit baffled by the fuel economy I have been achieving in my new (to me) boat for which we have had for about 3 months, and 20 hours. It is a 2004 with a 496HO, and at each fill up I seem to be averaging about 5 gal/hr of engine run time. I have filled up a few times, so I feel like the calculations are fairly accurate. What has me questioning this is it just seems very low compared to what I researched on these engines, so I was just curious if anyone else is as nerdy as I am when it comes to calculating economy at each fill up.

I know that driving style is a large factor in fuel consumption, so to be fair, we do have idle time through a river maybe, but I feel that gets balanced out with the few WOT runs out on the lake. Typically boating is probably a cruise at 30-40mph @ 2800-3500 RPM. I have compared my boat hour meter with actual routes I tracked on Navionics and even that seems pretty accurate.

I have been doing this for years, and for comparison, my previous boat was a 2003 190 Chaparral with a 220hp 5.0 Carb and I would average about 4 gal/hr, so I was expecting this boat to be around 8-10 gal/hr, considering the HP almost doubled and the boat weighs at least an additional 1500 lbs.

Thanks for your thoughts!

Idle time will make a big difference. I have a 502 and last weekend only used 13 gallons in 3 days on the water. Two of those days was just idling out in the cove to anchor, but the last day I raced a buddy with his Baja so we were wot for awhile. Then we did a 15 mile cruise running 30. I expected to burn much more fuel than what we did running wide open, but was suprised at the pump!
Btw, I won.

Ytmsn wrote: Fri Aug 17, 2018 8:41 am Idle time will make a big difference. I have a 502 and last weekend only used 13 gallons in 3 days on the water. Two of those days was just idling out in the cove to anchor, but the last day I raced a buddy with his Baja so we were wot for awhile. Then we did a 15 mile cruise running 30. I expected to burn much more fuel than what we did running wide open, but was suprised at the pump!
Btw, I won.

Awesome!

I agree that idling will make a difference, but I feel like I have managed to balance that out with my WOT and cruising speeds. Perhaps it’s just an efficient boat since it’s relatively ‘overpowered’, and the engine isn’t overworking, again not a bad problem to have!

Different engine, but the shape of the graph is probably the same...

viewtopic.php?f=28&t=1758

Nice info, this is more of what I was expecting. I think it’s why I keep putting gas in just to make sure I’m not crazy and don’t run out of gas. The economy has been good it me.

Big engines don't always been significantly more fuel. How hard the motor has to work plays a role.

This is a pretty cool site. http://www.boat-fuel-economy.com/outboa ... us-gallons

The figures will vary depending on application, but it at least gives you a general idea of fuel burn.

Yes I've used that site often. Last time out I did 3 laps around a 1x7 mile lake. 2 of them at low speeds and low cruising speeds. The last one I ran it pretty hard and I used 25 gals of gas in a few hours of running. It was pretty fun though.

I drive mine around and when the needle hits the 1/4th I put gas in it. I couldn’t even tell you what kind of gal/hr I get. It’s a boat not a Honda Civic.

tgrace98 wrote: Fri Sep 21, 2018 9:53 pm I drive mine around and when the needle hits the 1/4th I put gas in it. I couldn’t even tell you what kind of gal/hr I get. It’s a boat not a Honda Civic.

+1
Mine reads f before I hit the lake. All I know is the fast the boat goes, so does the gas.

Ha! My wife asked me to take her to someplace expensive for her birthday, so I took her to the gas dock..

Ytmsn wrote: Sat Sep 22, 2018 7:45 am Ha! My wife asked me to take her to someplace expensive for her birthday, so I took her to the gas dock..

Lol, that is the best thing I have heard in a long time!!

I'll have to get back to you in the spring with my 496. I don't drive normal with this much horsepower so my results could be skewed. But i'll try?