# fuel consumption 40hp Johnson



## aquaholic2 (Feb 17, 2010)

I have not been around mid sized outboards for many seasons, I run a 24' Thompson hardtop and know that bad side of fuel consumption as well as the skimpy consumption of my little kicker. I just set up a 91' Johnson VRO on my old 16' fiberglass Crestliner open hull, how long can I expect to run this thing on a 6 gallon tank....? Thanks for any references.AH2


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## aquaholic2 (Feb 17, 2010)

aquaholic2 said:


> I have not been around mid sized outboards for many seasons, I run a 24' Thompson hardtop and know that bad side of fuel consumption as well as the skimpy consumption of my little kicker. I just set up a 91' Johnson VRO on my old 16' fiberglass Crestliner open hull, how long can I expect to run this thing on a 6 gallon tank....? Thanks for any references.AH2


40 HP VRO.......


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## bustedrod (May 13, 2015)

if this helps I have an old 1986 90hp 2 strk merc on my 16.9 crestliner, with a 15 gal tank. on good water with 2-3 guys all my gear I can avg about 28 mi on a good day. that's runnin on plane about 35- 38 mph , I can run faster but I keep my rpm down below 4 grand , that's my sweet spot...lol mostly depends on load weight , speed, ect... if on erie maybe another tank . if not ? I had a boston whaler 14ft w/40 hp and I needed a second tank..


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## sherman51 (Apr 12, 2011)

carry a spare tank. should be able to run most of a day with a 40 hp. but it all depends on how you run the motor. there is no right answer.
sherman


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## Shad Rap (Nov 10, 2010)

aquaholic2 said:


> I have not been around mid sized outboards for many seasons, I run a 24' Thompson hardtop and know that bad side of fuel consumption as well as the skimpy consumption of my little kicker. I just set up a 91' Johnson VRO on my old 16' fiberglass Crestliner open hull, how long can I expect to run this thing on a 6 gallon tank....? Thanks for any references.AH2


Definitely all day if you're not making long runs.


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## Harry1959 (Mar 17, 2011)

Don’t know how much fuel you will use. But from my experience a 40 hp that’s working hard to push a loaded, heavier 15 ft boat at 25 mph will use significantly more fuel than a 60 or 70 hp that isn’t working as hard. At least that was my experience back in the 80’s.


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## freyedknot (Apr 10, 2004)

I could run out 12 miles on erie and troll and had enough gas. But always carried an extra 3gallons


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## G.lock (Apr 1, 2014)

If running at 5500 rpm you will use twice as much fuel as 4200 rpm. Had a force 40 hp on a 17' aluminum boat and dropping rpm made a huge difference.


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## aquaholic2 (Feb 17, 2010)

G.lock said:


> If running at 5500 rpm you will use twice as much fuel as 4200 rpm. Had a force 40 hp on a 17' aluminum boat and dropping rpm made a huge difference.


THANKS GUYS....I will take a small ( return) tank along until I figure this out......


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## firemanmike2127 (Mar 17, 2013)

Appx 4 GPH at wide open throttle. As has been mentioned by others here....backing off the throttle to a moderate cruising RPM will make a significant reduction in fuel consumption. Having a bit larger main tank would be an excellent idea.....especially on big water. A 3 gallon back-up tank is another option. Mike


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## sherman51 (Apr 12, 2011)

if you mix speed from idle to 3/4 throttle a tank should last most of the day. i had a friend with a 16' glass boat with a old 65 hp evinrude that he could run out on lake Michigan then troll all day and run back in and have gas left at the end of the day on a 6 gal tank. used a little more down on dale hollow running and gunning.
sherman


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## RJohnson442 (May 14, 2013)

A 1 hp motor at wot will burn 1 gallon of gas in an hour. A 10 hp at wot will burn 10 gallons in an hour and so on. You can then get a rough estimate of gas consumption from throttle position


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## bridgeman (Aug 26, 2010)

???... slight miscalculation there.. 10 hp will burn about a gallon an hour at WOT.. and a 250 will burn about 25 GPH. If it was 1 gallon per pony those quad 350 outboard rigs wouldn't be able to leave the dock without a 5000 gal fuel tank..


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## firemanmike2127 (Mar 17, 2013)

bridgeman is correct. On the older carbureted motors we always figured 10% of the HP rating @ WOT was an approximate fuel consumption rate. Some of the newer small engines w/ fuel injection are now a little bit more efficient. My first high horsepower motor was a 1979 160 cubic inch OMC V-6 rated @ 235 HP. It's a good thing fuel wasn't outrageous in the early 80's because that engine could really suck down the fuel. I had it on a Mystery 17' tunnel hull & all I wanted to do was go fast !! Mike


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