Spontaneous Avg Fuel Consumption Reset

[FootballYouBet]

So here's my update.

2nd tank of gas, just after I got below a half a tank, one notch below, the AVG MPG counter reset itself again just like it did with my first tank of gas. At the time it did the reset it said I was averaging about 25 MPG, about 3 MPG higher than it should have been. So basically consistent behavior I saw from the 1st tank of gas in that AVG MPG resets itself a little below half a tank. So when I got down to about an 1/8 to 1/4 tank I filled up again for the 3rd time I then did a manual calculation of MPG and compared to computer calculated MPG. Guess what? Computer was almost exactly the same as hand calculation at 22 MPG for computer with 22.3 MPG for hand calculated.

I have a hard time believing the people who say that their AVG MPG never resets during a tank of gas. I'm guessing that people aren't noticing the reset.

The bottom line is that in the end of the tank and even with the reset my hand calculated MPG vs computer calculated MPG is almost identical, which means that ultimately the MPG calculated for the tank of gas is accurate.

Now if I could only figure out why I am getting such a low MPG. I drive about 60/40 HWY/City and I'm not a lead foot, and I'm a coaster. I'm also running with ECO mode on. I have heard that I will get better MPG after 3,000 miles. I sure hope so.

[ryster]

I reset all of the readings at every fill-up. I only look at the AVG MPG display once a week (other than when I reset it) to see if it is "normal" compared to what it usually reads. I never leave it up long enough to notice if it ever resets randomly by itself.

Predominantly for me it is either Trip A or Distance to Empty on the display.

[FootballYouBet]

Another update

3rd tank of gas. AVG MPG counter did NOT reset itself this time. However it should be noted that for this tank of gas, I for the first time, shut off ECO Mode because I wanted to see what the gas mileage difference would be. What's also interesting is that for the last 2 tanks of gas when I was using ECO mode, that the hand calculated MPG and computer calculated MPG were almost identical. This time however, hand calculated MPG was 22.98, while computer calculated was 24.4.

So let's sum this up.

1. It seems that the AVG MPG gauge reset only happens if you have ECO mode on. I will have more concrete proof of this when I try the same thing with my 4th tank of gas.

2. If you run with ECO mode off, there will be a larger delta between your hand calculated MPG and the computer calculated MPG. Again, I will have more concrete proof of this when I try the same thing with my 4th tank of gas.

3. With ECO mode off I actually increased my MPG by about 1/2 of 1 MPG. My driving pattern for this week was identical to the last week. It's too early to tell if this is a trend. Perhas I'm starting to get better MPG anyway as the car is breaking in with 1,300 on the ODO? I'll have more data again next week.

Last, I will never run with ECO mode on again as now that I have run with t off I can't believe what a horrible effect it has on driving the car.

[Tom's.2012.SE2.0T]

Yes, I have the Nav system with Dimension Audio.