mpg

[kenmyfam]

Re: mpg

Sorry, according to Kenmyfam you don't need to know the speed, all you need is GPH ......

If you read the previous post of mine I did happen to mention ALL aspects. That would include All aspects. If you are getting 2 MPG in calm conditions you may get more with the current and wind in your favor or less if the current and wind are against you. Therefore ALL aspects need to be taken into consideration.
If I made a typo in my first post by not stating ALL aspects then I most humbly apologise.

 

[sasto]

Re: mpg

My flo scan reads GPH only......not MPG.....This trip involves a following current all the way to the Gulf. The poster will not be able to keep the same speed the whole trip. Barges to confront going either way, no wake zones due to marinas and private docks, bends in the river, etc. The first variable for us is GPH which can translate to MPG. I think the charts are a start in figuring some sort of basis for the best fuel economy. but you can throw it out the window making this trip. There will be alot of fluctuations in the MPG department but the GPH will have a tendency to remain the same hour after hour and be more accurate, as it is measured over a longer period of time. I take the GPH my scan reads and convert it into MPG. The river has milage markers to keep you informed as to where you are. If the trip involved going 25 kts constantly....MPG would be helpful. but thats not the case in this trip where the captain will have the need to vairy his speed frequently. Throtteling up and down is not in the charts.For us it is GPH converted into an average MPH. Happy boating, Bob and Bety

 

[kenmyfam]

Re: mpg

Nicely put sasto.

 

[jetmart]

Re: mpg

The answer to the post above is the Searay 240's best cruise speed is 23.3 MPH at 3000 RPM. It should be obvious if you look at the MPG column in the chart below which is for a 5.0L fuel injected 24' Searay. In reality, anywhere between about 23 and 35 MPH will give you almost identical fuel economy. Notice how GPH is irrelevent to this and hasn't even been mentioned? You could leave the GPH column out of the chart and it wouldn't make any difference to the discussion.

If you don't understand the relationship between fuel consumption and speed, the chart below will be pretty much meaningless to you.

To the original poster, I would figure on somewhere around 2 MPG depending on the age and load of your boat.

I agree totally with this. I have a 280 Sundancer with fuel flow computer. Anywhere between 2800 - 4000 RPM I am getting 1.4 - 1.5 MPG. Never deviates from this regardless of load wind etc. Obviously my speed is different at each RPM but MPG is the same. I am no longer concerned about high fuel burn per hour at high speeds when I know my MPG are unchanged.