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Just got my SGII. I still need to work on the settings. I have a '96 Accord 2.2L auto. When I let off the gas on a downhill the real-time mpg's read 9999. I've read about the fuel cutoff limit but would like a little guidance from the most experienced.

Also, what do you feel is the most important feature to be sure to set correctly to your vehicle? Speed? Cutoff? Fuel used (accurately)? Any suggestions or comments would be appreciated. Thanks

Just got my SGII. I still need to work on the settings. I have a '96 Accord 2.2L auto. When I let off the gas on a downhill the real-time mpg's read 9999. I've read about the fuel cutoff limit but would like a little guidance from the most experienced.

Also, what do you feel is the most important feature to be sure to set correctly to your vehicle? Speed? Cutoff? Fuel used (accurately)? Any suggestions or comments would be appreciated. Thanks
What you are seeing is normal operation of the SG. 9999mpg indicates that your car is in DFCO(deceleration fuel cut-off). I usually set the cut-off on the SG at just one number below what the GPH(gallons per hour) reads when the car is idling.

The way the SG calculates mpg makes it difficult to say that any one of those parameters is more important than the others. Unfortunately, the SG doesn't calculate mpg by dividing miles travelled by gallons used. It assumes a 14.7:1 air/fuel ratio and uses the engine size in liters and rpms and distance to calculate mpg. The easiest one to set is the speed setting. I did this by checking the SG against my Garmin navi unit. It would be difficult to get a SG calibrated to the accuracy of the hand calculation but all of the adjustments help to get it as close as possible.

When my car idles it is at .28 - .33 gph. So should I set the cutoff at 30 or so? I think that is what you meant? Thank you very much for all your help to all us "newbies"

When my car idles it is at .28 - .33 gph. So should I set the cutoff at 30 or so? I think that is what you meant? Thank you very much for all your help to all us "newbies"
I like helping when I can.:) As for the cut-off setting, since the car will idle as low as .28, I would set the cut-off at 27 or even 26. That way it won't accidentally trigger the 9999 condition if the car just idles down real slow as in very light throttle conditions when on very slight downhill stretches.