24' - 28' Best Range Fuel Economy

[searun]

Fuel econ is highly over-rated. Buy a big Grady with twins. They are planning to build a pipeline from Alberta just to keep me fishing. 16 US Gal/hr if I drive like an old woman. 17 - 20 if I drive like normal, and 28 to 30 if I drive like a teen ager. My buddy had a 27 foot Seasport with volvo diesel and he paid about 1/3 my bill. Diesel rocks. Hoping some rocket surgeon develops a reliable diesel outboard soon.

 

[Red Monster]

If you don't plan the tide current or the river current you might end up being short of fuel.

True, but you said 6 GPH, so tides and currents are irrelevant. Of course stuff like tides and currents will cause you to burn more fuel.

 

[Jimmy]

Two years ago I bought a 20ft bertram moppie that had been restored and had a 220hp turbo yanmar diesel put in it. It is a fun boat and what makes it even more fun is at 26mph cruise it burns 6mpg with a range of 260 miles.
you guys are correct that diesel gets you a lot better mileage but it has increased service/ maintenance
costs.
It is entertaining watch people turn and stare at the sound of a diesel in a 20ft boat.

 

[Gunsmith]

I you are traveling against a tide of 4knts you have to overcome that speed before you are even moving , so they can't be irrelevant.

True, but you said 6 GPH, so tides and currents are irrelevant. Of course stuff like tides and currents will cause you to burn more fuel.

 

[Rum Buddies]

I you are traveling against a tide of 4knts you have to overcome that speed before you are even moving , so they can't be irrelevant.

it matters in MPG but GPH is how much you're burning in an hour of running, doesn't matter if you're sitting in one place bucking the tide or flying 50mph

 

[Gunsmith]

So why burn fuel if you do not go anywhere?

 

[Sr SQ]

Those 135's are the only 3 star V6 2 stroke outboards that Mercury produces i believe. That boat gets 15% better mileage than the Grady Gulfstream with twin 150's that i used to own. I tried 4 different prop setups before i ended up with the 4 blades. I forget what the pitch is and my boat is in Port right now so i can't check. I run at 3900 rpm to get my max performance.

Rev 4s are the props I ordered so we will see if they are the props for me?
According to my flowscan I get the same mpg 34-3900rpm but thats with the mirages I am running now.
I would gladly give up some speed for mpg since I need pretty good water to run 4k with these motors turning 21" props

 

[TenMile]

Diesel -- bah. Outboards -- bah. Gas -- bah. Forget all of those. How about a 33' cruiser that can travel 20mi and use no fuel at all? Of course, $330K buys lots of gas. On the upside, you could literally fish all day and not make a noise. Switch the diesel on and it gets 8mpg cruising at 7kts.

http://www.popularmechanics.com/out...-boat-hybrid-power-catches-a-current-15244084

 

[Aces]

Rev 4s are the props I ordered so we will see if they are the props for me?
According to my flowscan I get the same mpg 34-3900rpm but thats with the mirages I am running now.
I would gladly give up some speed for mpg since I need pretty good water to run 4k with these motors turning 21" props

Hope those work out for you. My dealer (RPM) had several test props that i tried before i bought the ones i have now.

 

[shamrockin]

I have a 27 ft. Shamrock mackinaw with the 315 hp. Yanmar.it cruises at 25 mph at 8 gph. Which I guess is 3.1 miles per gallon,the range with a full load of fuel is on the high side of 400 miles.i really like the torque of the diesel,very nice on those long hills running back in.

 

[trophywife]

nice boat shamrockin....

 

[captmike]

gas vs diesel -great articles and comments on boatdiesel.com

 

[captmike]

Here is what I know, if someone is concerned with fuel economy then they cannot afford it, and a smaller light boat with a diesel gets better GPH than a heavy gas boat. Nonetheless, in this length range, does anyone have some good advice? Thanks

google David Pascoe article on gas vs diesel

 

[Gong Show]

google David Pascoe article on gas vs diesel

Okay, had a look at his article, not too impressed.
Some of it is common sense, but the hours to overhaul 'myth' does not jive with my extensive experience.
Also it is dated. Written in 2001 before common rail diesels were available for recreational boats and advances in gasoline engine technology.
Just a warning to not treat the article as gospel.

 

[captmike]

Okay, had a look at his article, not too impressed.
Some of it is common sense, but the hours to overhaul 'myth' does not jive with my extensive experience.
Also it is dated. Written in 2001 before common rail diesels were available for recreational boats and advances in gasoline engine technology.
Just a warning to not treat the article as gospel.

search gas vs diesel on boatdiesel.com esp Tony Athens articles (he is a moderator on boatdiesel)