Average MPG on OBC

[wjbell]

How long of a time period does the OBC take into account to figure the average MPG? I just took a trip where I drove 370 miles all freeway and the OBC was fluctuating around 17.5 for average MPG. But when I got back and filled up my tank (it was topped off when I left) it took 17 gal, which for 370 miles equals 21.7 MPG.

The math doesn't lie so what could be wrong with the OBC?

[winfred]

when you go on a trip reset the mpg for a more acurate reading, theres a mpg 1 and mpg 2 if you hit the button another time pick one and hit the reset button and it will start over

[wjbell]

Ah, user error. That makes sense. :) So I take it the OBC calculates MPG indefinitely until it's reset?

[Fetch]

Ah, user error. That makes sense. :) So I take it the OBC calculates MPG indefinitely until it's reset?

yep, or if you disconnect your batt

[digitaldragon03]

What i usually do is use mpg 1 for trips, so its constantly being reset. MPG 2 i leave alone so i know what kind of gas mileage im getting in the long run.

[Fetch]

What i usually do is use mpg 1 for trips, so its constantly being reset. MPG 2 i leave alone so i know what kind of gas mileage im getting in the long run.

Very similar to what I do.
mpg1 I reset with every tank fill & check against my own MPG calculations (it's always pretty much dead on). Then I have never reset mpg2 since I bought the car. Hope I don't have to disconnect the battery! haha

[Michael999]

I set MPG1 every time i fill up my tank, and then at the end of the tank i check if its accurate or not.
Sometimes its been way off.
I use MPG2 for short trips, or just if im wondering how many MPG im getting on a certain road or traffic.
I get 15-16L /100km, i wished it was more :(

[3rdE34]

What i usually do is use mpg 1 for trips, so its constantly being reset. MPG 2 i leave alone so i know what kind of gas mileage im getting in the long run.
__________________ ditto here

im getting 12-13/L 100km 50% freeway normally spirited driving when i use "premium" fuel ie 98 octane i dont do much better.. im happy with my fuel usage and the bowser price is down wooohooo

[632 Regal]

my OBC is about 2 mpg lower than actual. There is a way to adjust for this in the OBC.

[Airborne001]

There was a post very recently about how to re-program your computers calculation to make it reflect much closer to your actual mileage.

[Russell]

same here. Just something for fun while driving.