mpg readout margin of error
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#6
I just did a big trip and mine read the opposite. The computer read 19.2 though hand calc'd I cleared 20.6 or 17.794 Gallons of Fuel for a 368 mile trip on mixed highway conditions.
My computer used to be closer to exact, until I changed to a Hipotek TB and the Superchip tuning. I think the most noticeable variations came shortly after the tuner.
I agree though, if you are running 10 MPG, either you are calc'ing something wrong like not starting out on a completely full tank, or you are constantly full throttle on and off, but still that shouldn't give you 10 mpg. My worst was like 12 or 13 mpg, but I had 2500-3000lbs on a trailer and I wasnt gentle...
My computer used to be closer to exact, until I changed to a Hipotek TB and the Superchip tuning. I think the most noticeable variations came shortly after the tuner.
I agree though, if you are running 10 MPG, either you are calc'ing something wrong like not starting out on a completely full tank, or you are constantly full throttle on and off, but still that shouldn't give you 10 mpg. My worst was like 12 or 13 mpg, but I had 2500-3000lbs on a trailer and I wasnt gentle...
#7
I went from a full tank to a 1/8 of a tank and I got a 186 miles out of that. I try to be easy coming off stop lights. The only time I really get into it is when I'm on the highway and I pass somebody. Other than that, whether it's city driving or highway driving, I'm fairly tame with the throttle. I just swapped out my air filter and that helped a little bit so I still think my crappy mileage has an underlying cause. Problem is money don't grow on trees so even if I knew what it was, I still might not be able to fix it.
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#8
I went from a full tank to a 1/8 of a tank and I got a 186 miles out of that. I try to be easy coming off stop lights. The only time I really get into it is when I'm on the highway and I pass somebody. Other than that, whether it's city driving or highway driving, I'm fairly tame with the throttle. I just swapped out my air filter and that helped a little bit so I still think my crappy mileage has an underlying cause. Problem is money don't grow on trees so even if I knew what it was, I still might not be able to fix it.
The algorithm used to calculate fuel flow in the PCM can be off by a fair margin since there's no "flow volume sensor" so it needs to do a best guess on how much fuel is used per squirt plus the other factors that it can sense to come up with it's guesstimate.