ML350 Bluetec Computer MPG vs Real MPG
03-21-2011, 09:16 PM
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2019 GLC 300
ML350 Bluetec Computer MPG vs Real MPG
Has anyone noticed a significant variance in the computer calculted MPG vs the old divide the mileage by the gallons method ? I got about a 3 MPG differece on my last tank and I am almost certain I had it topped off both times. Of course the computer calculated mileage is always the higher one....
Last edited by davatk; 03-21-2011 at 09:27 PM.
03-22-2011, 07:59 PM
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Has anyone noticed a significant variance in the computer calculted MPG vs the old divide the mileage by the gallons method ? I got about a 3 MPG differece on my last tank and I am almost certain I had it topped off both times. Of course the computer calculated mileage is always the higher one....
03-22-2011, 09:30 PM
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Shouldn't make any difference how you top up the tank as long as it is consistent each time. I always reset the trip odometer each fill up so it is an easy calculation.
03-23-2011, 09:27 AM
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Yea, only thing is I filled up (and topped off) at 2 different service stations. Sometimes the slope of the pumps can make a bit of difference, as well as the "foaminess" of the fuel. It may just be simpler and more accurate to make sure you set the fill rate at the same speed each time and go to the "first shutoff" and leave it at that when checking mpg manually. Topping off diesel is a pain...
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03-26-2011, 11:14 PM
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Well, I checked it again filling up at the same pump and topping off to the top of the filler neck again. Still off about 2.3 mpg. (28 on computer, 25.779 via manual calulation). I'm gonna try it again, but this time just fill to the first click on the nozzle both times and see what I get. If it is that far off it would seem that may be unacceptable for a 60K vehicle. I had a ScanGuage that cost $150 and was very accurate.
03-28-2011, 10:44 AM
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Under my gas filler cap (ML550) there is a sticker that says DO NOT TOP UP. Like that, in caps. Maybe one of the reasons is for accuracy of the computer.
03-28-2011, 11:10 AM
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If you are concerned about variation from each filling, then just track it over 2 or 3 tank fulls. It will average out, but still give a good comparison to the computer if you do not reset it.
03-28-2011, 04:09 PM
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All cars say that now. It can overfill and cause extra pollution. It is reccomended by everyone to just fill up until the hose pops shut and then stop.
If you are concerned about variation from each filling, then just track it over 2 or 3 tank fulls. It will average out, but still give a good comparison to the computer if you do not reset it.
If you are concerned about variation from each filling, then just track it over 2 or 3 tank fulls. It will average out, but still give a good comparison to the computer if you do not reset it.
04-15-2011, 10:25 PM
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All cars say that now. It can overfill and cause extra pollution. It is reccomended by everyone to just fill up until the hose pops shut and then stop.
If you are concerned about variation from each filling, then just track it over 2 or 3 tank fulls. It will average out, but still give a good comparison to the computer if you do not reset it.
If you are concerned about variation from each filling, then just track it over 2 or 3 tank fulls. It will average out, but still give a good comparison to the computer if you do not reset it.
Anyone know if there is any way to calibrate this ? Or possibly a software update ? I had a $150 scan guage once that was much more accurate than this.
