gas mileage

[The Hillbilly Barge]

what eng rpm will provide optimum fuel mileage

 

[CLDave]

Depends on dozens of variables. There's a huge thread on performance that many, many owners have weighed in on - so I'd start there.

That said, for me (R25 with a 350 Merc Verado) optimum balance for cruising is around 30-35 mph, which is about 3800 RPM (guessing). WOT I'm at 51 MPH and 6200 RPM.

 

[The Hillbilly Barge]

i will try and find it, thanks

 

[Remediation]

I am just going to say it. If you are worried about MPG don't buy a boat. The boaters that are traveling the Great Loop need to take that into consideration for calculating their mileage during their travels. Boating meanings getting a lot of gas every once in a while and your family will spend more in the Marina then the gas bill. Boating is luxury. Share it and enjoy it.

 

[The Hillbilly Barge]

not worried just just trying to get a grasp of what would be a happy medium, we also own a motorhome so gas mileage isn't my primary focus.

 

[Michiman]

Welcome Dale! I've got a GCW 2574 with a 250 Mercury Verado and according to Mercury Vessel View, my best economy (2.9 MPG) comes in at about 18 MPH. Of course, it also depends on loading and lake conditions. Like CLDave suggested above, there are many variables that come into play so you'll have to do some trial and error to find your sweet spot. Good luck and report back.

 

[The Hillbilly Barge]

As soon as weather permits, I'm going to test it out

 

[Potomacbassin’]

Hey Hillbilly (proper noun) -

Besides at very low displacement speeds (5mph), best fuel efficiency will generally be right at planing speed. That will depend on many factors including # of toons, toon length and diameter, weight, etc. but it appears to be in that 16-19mph range for our boats. After your boat gets up on plane MPG will then generally slowly decrease as your wetted surface creates more and more drag.

But as CLDave noted, many of us want to get to point B in a reasonable time as well so there is a balance between speed and efficiency (cruise). For me that's around 40 mph or 5000rpm. That of course will also depend heavily on motor output and prop selection.

 

[PartyBarge]

what eng rpm will provide optimum fuel mileage

The best cruise MPG for most reasonably matched motor/boat combos will fall between roughly 3500 to 4000 RPM (typically, MPG at near idle will be better, but slower than most want to go). Find a combination similar to yours in the Yamaha Performance Bulletins for more detailed and specific info. Those tests are the gold standard covering a wide variety of boats.

 

[Vikingstaff]

The great thing about boats and pontoons is the bigger the motor & boat, and the faster you go...the better the fuel efficiency gets. It’s really science.

* I am not responsible for any lies I spread in my online life. I blame that on others. ha, ha.

 

[The Hillbilly Barge]

The its really science and disclaimer at the end are great, you should get into politics

 

[CLDave]

Also worthy of note that BoatingMag has reviews that include efficiency and top speed. Here's a Benny archive page: https://www.boatingmag.com/tags/bennington/

Example review: https://www.boatingmag.com/story/boats/2021-bennington-24lxsba-bbg/