[gman19]

I guess this is the norm...our '06 G6 was always high. Our '10 Equinox is always high. And my Cruze is always high. I wish they were more accurate. And yes, just to clarify, I fill up at the same place 90% of the time, and wait for the same pump most of the time. Method, lock handle to slowest flow rate until it clicks off, then I manually go slowly to one more click. Have done this for years.

I do wish they were more accurate, I use them mainly as an indicator, then subtract about 10%.

 

[gman19]

I don't know what to make of this at all. I don't pay attention to the MPG on the DIC but i reset it with fuel used. It said 12.6 gal used when I filled up today and the pump clicked exactly at 12.6. The last couple times I've been able to squeeze a lot more fuel after the click. This is the third straight time my light came on at exactly 12.6 gal, which makes me think the tank is 12.6 gal for all models with 3 gal of "reserve." I don't understand if it draws fuel from the reserve though...?

This is what gets me as well...last fillup, DIC said I'd used 12.1 gallons, the Low Fuel Warning just came on as I arrived at the pump island. I proceeded to (one click method) put 13.3 gallons into the tank.

I drove 456 miles on that fillup:
Calculated: 456 miles/13.314 gallons = 34.249mpg.
DIC Numbers: 456 miles/12.1 gallons = 37.7mpg.

DIC Estimate was 37.6mpg. So....is it calculating correctly but measuring fuel consumption WRONG....that appears to be the case....the algorithm for fuel economy is probably the simple one we use. Distance is measured correctly, but consumption.....'nother story, IMO...

 

[gman19]

Only 6 fillups so far, but the DIC in my Eco is pretty far off: 8-10%. And we drive quite conservatively.

^^ Me too...I really am trying to see what the car will get economy-wise. Driving really conservatively. My LTZ seems to read about 8-10% high.