ive seen a couple guys on here go on road trips and not use the average miles per gallon. so those of you who did calculate manually..how accurate was the average compared to how many miles you actually got per gallon?

The average stops averaging after the car has been turned off for like... 4 hours. But i guess it could still work if you filled the tank completely, went on a road trip then stopped for gas and filled up again and then calculated the average. Hmmm i'd be interested to see how accurate it is.

You can change it not to reset the averages. It is under settings on the display.

Yes, I know that it does but the memory still only holds it at 4 hours. at least I'm pretty sure because every morning my MPG seems to reset.... maybe I am wrong though.

its pretty simple math

How do you toggle through the display? I mean there is the info button but I cannot select settings on the display

This is how it works on my lancer... look me a few tries to get this right. But, engage parking brake and turn the key just short of ignition, to where you hear the injectors/relays ticking. Now, press info until you see Settings. Then hold down info to enter the menu.

Yeah mine resets no matter what setting it is on.

Has anyone actually left the car for more then 4 hrs and had the mpg still there afterwords?

That's a good question, too. I think it holds it because I've driven it all day with breaks in-between of less than 4 hours and it maintained the av and picked up where I left off.

the avg on my lancer is actually pretty accurate.
i did a whole lot street driving this whole week and it said 26.3 mpg. and when i did my manual count earlier to fill up, it said 26.223 mpg. pretty accurate.

Lucky you, I'm normally under the 20 mpg mark.

Mine is always optimistic by about 1 mpg.

Lucky you, in NYC, stop and go city driving, I get 12-13mpg.

^ ouch

somewhat off-topic... but the latest 0020 reflash seemed to help significantly with milage. I was previously getting 19-20 mpg on my commute to/from work.. now easily get 22mpg on the exact same trip. yes, the car-puter is pretty good at calculating milage... at least as accurate as the fill up, drive, fill up again method of calculation, if not moreso.