How do you measure fuel flow/consumption?

[fastang50]

First off, new guy here, have lurked the forum for info for awhile now but have some questions that I haven't found direct answers to so figured I'd better become official! Looks like a really helpful site, so looking forward to interacting with you and hope I can add some value along the way.

Fuel consumption is the question of the hour, my father and I are planning a river trip (Lower Mississippi) and fuel management will be a big darn deal. I'll post another thread in the general forum about adding fuel tanks. Anyhow.....

I need to know, accuratly, what the fuel consumption of this boat is during operation. It seems that there are two options, the Flow Scan or Faria type fuel meters, essentially a gph output that I would cross with GPS MPG to find a sweet spot for cruise, or a Chartplotter Fuel Flow add on sensor that essentially gives real time MPG.

Which ones have you used and how accurate do they really prove to be? Barring negative feedback, I'm leaning to the Garmin Chartplotter type, since I think the combo unit would be handy.

What has your experience been? Oh yeah, powerplant is the common 260 Mercruiser, think an MC-1 outdrive from what I can tell. Boat is a Sea Ray 245 Cuddy Cruiser, suspect it will weigh about 6k# loaded out for the run.

Thanks!

 

[79Merc80]

Re: How do you measure fuel flow/consumption?

I am using the Flow Scan alone. It's VERY accurate. There is a model that will hook up to a GPS and give you MPH.

Hope this helps, Craig

 

[sasto]

Re: How do you measure fuel flow/consumption?

I am using the Flow Scan alone. It's VERY accurate. There is a model that will hook up to a GPS and give you MPH.

Hope this helps, Craig

I'm with Craig. I have only used Flow Scan in several boats. My sucess is the same as Craig's....very accurate!

 

[fastang50]

Re: How do you measure fuel flow/consumption?

Thanks, good to hear.

Any "best price" recommendations and particular model that you like?

 

[79Merc80]

Re: How do you measure fuel flow/consumption?

Buy it from their web site. Mine was 498 (I think) instead of over 700 retail.

 

[E4ODnut]

Re: How do you measure fuel flow/consumption?

You might find this thread of interest.

http://www.baylinerownersclub.org/forum/showthread.php?66274-Accuracy-of-fuel-flow-meters

 

[79Merc80]

Re: How do you measure fuel flow/consumption?

Here is the link for the Flow Scan you would want.

http://www.floscan.com/html/blue/seriesdetail.php?sid=13&catid=2

Craig

 

[Silvertip]

Re: How do you measure fuel flow/consumption?

Without spending a bunch of money, fill the fuel tank. Launch the boat at a spot where you know the exact distance to a particular location say 10 miles away, or using a simple hand held gps head out at a speed that provides the comfortable cruise rpm you like. Make the run at least 10 miles and then head back so you have traveled about 20 miles. Fill up the tank under the same exact conditions as you did before starting the trip. You know how many miles you traveled and you now know how many gallons of fuel you used. Divide the gallons into miles and eureka -- you have x.x miles per gallon. Obviously that number will never be constant because just like your car, faster speeds uses more fuel. More people in the car uses more fuel. So do the test with what you consider the load will be on your long trips. Rule of thumb: plan on 1/3 of your fuel load going out, 1/3 coming back, and 1/3 for emergency. Fuel economy for boats changes but a heavy load my produce 2.5 MPG while the same boat with a light load may get 3 MPG. At wide open throttle you can figure roughly GPH at 10% of the rated HP.

 

[fastang50]

Re: How do you measure fuel flow/consumption?

Thanks for the low buck suggestion Silver.

That floscan with the build in tach looks great! The price unfortunatly, about what a chartplotter with a fuel sensor would cost.

Anyone know if the dedicated floscan system is more accurate that the Garmin add on fuel sensor for their GPS systems?

You folks are sure helpful, appreciate it.

Have a few home projects to wrap up, then this boat gets a new steering rack/cable, shift interrupt switch, and it will be time for some sea trials. We'll need the fuel measurement for that.

 

[Howard Sterndrive]

Re: How do you measure fuel flow/consumption?

you can get a Lowrance LMF200 for around $160... mine works well for showing GPH. I added a GPS unit for MPG, but if you just want flow rate, the Lowrance is a cheaper option.

 

[Silvertip]

Re: How do you measure fuel flow/consumption?

Thanks for the low buck suggestion Silver.

That floscan with the build in tach looks great! The price unfortunatly, about what a chartplotter with a fuel sensor would cost.

Anyone know if the dedicated floscan system is more accurate that the Garmin add on fuel sensor for their GPS systems?

You folks are sure helpful, appreciate it.

Have a few home projects to wrap up, then this boat gets a new steering rack/cable, shift interrupt switch, and it will be time for some sea trials. We'll need the fuel measurement for that.

Look at the specifications for the various units. Flow rate accuracy is only as good as the accuracy of the sensor and its proper installation. The specification will tell you the minimum and maximum flow rates and the amount of error expressed as +/-xx%