fuel mileage

[azzkiker]

Im new at outboards and pontoon boats, I have a question on fuel mileage. I have a 1997 Crest Sport 22 foot with a Mercury 60 hp big foot 14 inch prop 10 pitch WOT 5400 rpm with one person.
The motor runs great 125psi in all three cylinders but this thing uses fuel like crazy, it has two 12 gallon tanks. I can put in and travel to a sand bar approx. 7 miles away with four adults on board running about 5000 rpm not wide open. In this distance it will burn about 6gallons does this sound normal? After a couple trips im looking for more fuel, Its nothing to burn 24 gallons in a day.

 

[ahicks]

Think 4 stroke. My 90 Honda w/carbs won't use 24 gallons in an entire season. Fuel injected motors do even better and run great - until they don't......

Another thought too. While pontoons are absolutely great, I've had one for the last 40 years or so, when you've got a favorite destination that's an hour or more away (one way), suggest you have a look at deck boats. They cruise just as well, and can cover much more ground when you're in a hurry. An outboard powered (stay with that 4 stoke thought) 20-22 footer is often the best of both worlds. My thought anyway, FWIW. -Al

 

[Earl Cordova]

At my normal cruising speed of 32mph I get 2.5 gal/mile or 12 gallons/hour.
My last boat was a 4.3L in a 18 foot cuddy cabin at 28mph and got 3.5 gal/mile.

 

[Rabbit929]

My 90F 4 stroke yamaha 21ft sylvan seems to pretty darn fuel efficient, but at WOT it doesnt hesitate to chew up gas when heavily loaded and towing a tube.
I 2nd what ahicks said, if your actually planning to cover some reasonable amount of ground and are concerned with fuel efficiency, a deck boat might be the best idea. It takes double the power for a pontoon to even shake a stick at a regular boat as far as speed goes, my 90hp will still do 25-28mph, but only 18mph when at capacity. At that point im plowing enough water to almost compete with the wake surf boats.

 

[HotTommy]

Consider this food for thought. The rule of thumb is that a typical outboard burns about one gallon per hour for every ten horsepower produced. If you are running near WOT for an hour, you'll burn about 5-6 gallons. If it takes you about an hour to travel seven miles to the sand bar, that is what it will take. ..... My former boat had a modern 4-cycle engine with a gauge that showed the gallons per hour at any RPM. By cross referencing that with my GPS MPH I was able to calculate my MPG for RPMs from 1500 to WOT. I discovered that my best MPG (6.2) was at 3000 RPM and it didn't drop off too much until I went about 3500 RPM. After that it dropped like a rock to around 2.6 MPG at WOT. Of course my boat was quite different from yours, but the principle of fuel consumption applies. Non-planing pontoon boats are very inefficient at high power settings.

 

[Toyelectroman]

My mercury 115 will burn at WOT 5800rpm 10gph, I normally try to stay at a cruise speed so it only burns 4-6gph

 

[Mechmagcn]

As others have said, on a pontoon boat you're going to burn a lot of gas above cruising speed. My 18' Bass Buggy with a 40hp Tohatsu 4 stroke sips gas below 4K, but at WOT it burns probably three times as much with very little increase in speed.

 

[Sea Rider]

If the max wot rpm range for said motor is 5500 rpm and with a 10 pitch solo boating it's revving at 5400, with a load of 4 up should be dropping wot rpm to the lugging side of 5000 rpm or under. If plan boating constantly with 4 up should prop the motor better to run towards its max wot range of 5500 rpm by dropping pitch with a 9-8 prop. Once there should attain equal speed with less throttle use than when with a 10 pitch, consequently bettering the motor's fuel consumption.

Marine motors are fuel guzzlers if comparing mileage with cars in the order to at least 3 to 1. Having fun in the water has its cost, besides who said that boating was a cheap sport. LOL!!

Happy Boating​