Jet MPG vs inboard engine

[shackle101]

So I've been looking at a lot of the boat test reviews vs. some inboard engines. It seems inboards get 2-3x better gas milage at certain speeds. I know we don't buy boats for gas mileage, but at $4-5 a gallon, it's something to consider, I suppose. Is the MPG pretty accurate from boat test reviews for newer Yamaha models?

 

[Babin Farms]

We were worried about the same thing after coming from a fuel sipping outboard but after having the Yamaha for quite a while I am very pleased with the fuel consumption. Any boat can get bad mileage, just go full throttle but if you find that nice cruising speed it's a lot better fuel economy.

 

[Dough]

Boat trip with friends. We had a weekends worth of drink and clothes on the boat. 2.7 over 51 miles

 

[shackle101]

Thanks! Yeah, I'm curious how each performs with a loaded boat. I know boat tests usually only had two people and 50lbs of gear. I'll always have more than two people.

 

[FSH 210 Sport]

For my boat the mpg is really close to the test mag’s mileage.

In boat test of my boat they only had three people, 50% fuel =150#, 50 lbs of gear and the mpg was 3.5.

Normally I have about 500# of gear ( that includes the trolling motor and batteries and the live well full which is 216# of water) at full fuel and me on board I was getting 3.375 mpg =218.7 mile range (with extra 22 gallon tank) all with the stock impellers.

With the high altitude impellers my solo mileage dropped to 3-3.1 mpg=194 mile range (w extra 22 gallon tank) a totally fair trade off for the huge improvement in performance, toss in two adult guests and their gear and the mpg drops to roughly 2.8 mpg=181 mile range (with extra 22 gallon tank) All at best cruise speed of roughly 25-28 mph. If I knew I was going to be operating at sea level or low altitude I’d throw the OEM impellers back on.

Edit: Should have thrown this in there.. at WOT I’m burning 14.5 gph at 39mph which works out to 2.68 mpg. Which works out to a range of 168 miles with my extra 22 gallons of fuel.. thanks @Liveto99

All of the range estimates are with a 10% reserve of fuel, thats 7.4 gallons of reserve with my Moeller 22 gallon deck tank.

 

[fatboyroy]

In my experience, 3 people vs 1 and 150lb gear I dont notice much difference in fuel mileage 2.5 to 3.5 . The ocean condition is what swings it the most for me, when its really rough i can run 1.5mpg

Edit. this is also the reason why jetboaters bring extra can of fuel crossing 50mile to bimini... Jetboat range is 150 miles easy but on rough condition they can run out of fuel.

 

[Neutron]

I had a 26 foot four winns vista cabin cruiser prior to my ar240 and it burned roughly the same fuel. The vista had a 270hp volvo penta duoprop. Top speed was 45mph. It was much heavier than the ar240 by 1000lbs.

 

[Thermobrett]

I believe I average 2.3 MPG with 2 adults and 3 kids running roughly 32-34 MPH. Probably better if I bring down the speed to 26-30 MPH, but whats the fun in that