How to calculate GPH on mefi4.adx
Moderators: Mangus, robertisaar, dex
How to calculate GPH on mefi4.adx
is there anyway to calculate GPH (gallons per hour) in real time and calculate total gallons used as a cumulative figure, in total and per trip.
Would like to be able to use this software (i know is not intended for this) to calculate how many gallons i have used on my boat while underway.
bear in mind as this is a boat and not a car i do not have a speed sensor built into my defenition ADX file so cannot calculate MPG. i need to put a certain amount of gallons in boat and let the software monitor how many gallons i have used...am sure is possible someway ?
i would have to use the injector flow data in someway...
Would like to be able to use this software (i know is not intended for this) to calculate how many gallons i have used on my boat while underway.
bear in mind as this is a boat and not a car i do not have a speed sensor built into my defenition ADX file so cannot calculate MPG. i need to put a certain amount of gallons in boat and let the software monitor how many gallons i have used...am sure is possible someway ?
i would have to use the injector flow data in someway...
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Re: How to calculate GPH on mefi4.adx
There is a native GPH item built into the MEFi4. What software are you using? If you are using the OBD Diagnostics software (aka MEFIBurn) there should be a GPH item already in your items list.pbusanga wrote:is there anyway to calculate GPH (gallons per hour) in real time and calculate total gallons used as a cumulative figure, in total and per trip.
Would like to be able to use this software (i know is not intended for this) to calculate how many gallons i have used on my boat while underway.
bear in mind as this is a boat and not a car i do not have a speed sensor built into my defenition ADX file so cannot calculate MPG. i need to put a certain amount of gallons in boat and let the software monitor how many gallons i have used...am sure is possible someway ?
i would have to use the injector flow data in someway...
Since you do not have a speed sensor you cannot get an accurate MPG reading; however you could get something reasonable by using the RPM output. I did this with a car, but of course it was accurate only in high gear. In a boat this method would not be as accurate since there are many more variables other than RPM which affect the speed.
Charles
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You would have to know (or estimate) your boat's speed at a certain RPM. In the item list equation you would link both the RPM and the GPH. The RPM would have to have a factor that would convert it to the correct MPH. Then just divide the converted RPM (converted to MPH) by GPH.
In my case the equation was X /20/ Y, where X=RPM and Y=GPH. 20=factor to convert RPM to MPH. The factor for your boat will be much larger. Assume your boat is turning 2000 rpm at 10 mph, the factor would be 2000/10=200.
Charles
In my case the equation was X /20/ Y, where X=RPM and Y=GPH. 20=factor to convert RPM to MPH. The factor for your boat will be much larger. Assume your boat is turning 2000 rpm at 10 mph, the factor would be 2000/10=200.
Charles
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ok thanks...hmm could be something to look into..considering we have fuel flow rates and engine hours and rpms all captured there should be some way to accumulate gallons used over time...
HI Mark maybe something that can be incorporated into your software ...
Could history tables be used in anyway for this ..
HI Mark maybe something that can be incorporated into your software ...
Could history tables be used in anyway for this ..
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- Author of Defs
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one way to estimate fuel usage would be to take the GPH reading, average it(can be done with the histograms, then multiply it by the amount of time the engine has been running(done in hours to make the conversion easy).
avg 5 GPH over a 2 hour period = 10 gallons used
it's obviously not automatic, but it's fast to do.
avg 5 GPH over a 2 hour period = 10 gallons used
it's obviously not automatic, but it's fast to do.
on a boat this would be very inaccurate as we deal in large values and large variations in consumption.robertisaar wrote:one way to estimate fuel usage would be to take the GPH reading, average it(can be done with the histograms, then multiply it by the amount of time the engine has been running(done in hours to make the conversion easy).
avg 5 GPH over a 2 hour period = 10 gallons used
it's obviously not automatic, but it's fast to do.
ie can be trolling at 1.5 GPH and cruise at 5 GPH and open throttle up to 13 GPH, averaging such values over time would give huge variations depending on time spent at each speed.
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- Author of Defs
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i do this constantly for fuel economy calcs...
take trip duration, convert it into decimal format of hours, multiply it by average GPH over the entire trip, then you have fuel used.
if you were to mess with something that has an accurate vehicle speed signal as well, then you can also calculate average speed in the same fashion and come up with total distance traveled.
using those two values(fuel used, distance traveled), you generate a very accurate MPG value, within a few percent of error.
take trip duration, convert it into decimal format of hours, multiply it by average GPH over the entire trip, then you have fuel used.
if you were to mess with something that has an accurate vehicle speed signal as well, then you can also calculate average speed in the same fashion and come up with total distance traveled.
using those two values(fuel used, distance traveled), you generate a very accurate MPG value, within a few percent of error.