Fuel Economy / Gas Mileage Sticky Index (look here for good info)

[cyclopathic]

question: do i still have to put a Fuel log even if i didnt had a full tank? or the Fuel log is only for full tank?

Not 100% sure how to interpret your question; do you mean you:
a) topped off tank and only put 2-3 gallons to fill it up?
b) or you added 2-3gal at expensive gas station just to get home?

if A) than you can enter data mi/km and litter/gal and reset trip meter.

If B) write down how much gas you put, do not reset trip meter and add liters/gallons you wrote down to total. So you may end up with something like 536mi, 11.7gal entry good luck

[mitsumi]

The log is meant for complete fill-ups. Otherwise you don't know your actual fuel consumption.

The Mirage's onboard fuel economy display is reasonably accurate, but not 100%.

ok, but what shall i do with my next full tank? do i just put the last reading even if i didnt have it full tank or should i put the last reading when i had it in full? sorry so noob about this haha

[mitsumi]

Not 100% sure how to interpret your question; do you mean you:
a) topped off tank and only put 2-3 gallons to fill it up?
b) or you added 2-3gal at expensive gas station just to get home?

if A) than you can enter data mi/km and litter/gal and reset trip meter.
If B) write down how much gas you put, do not reset trip meter and add liters/gallons you wrote down to total. So you may end up with something like 536mi, 11.7gal entry good luck

i only filled up when the last bar was blinking, i gassed up only about 4 bars in my guage not full tank.

[cyclopathic]

i only filled up when the last bar was blinking, i gassed up only about 4 bars in my guage not full tank.

Then no prob just enter distance/amount to fill up.

The point MetroMPG was making that you need to fill it up to the same level each time, otherwise you have no point of reference. Fill to full isn't 100% accurate because you would still get different results depending on pump adjustment and car tilt, but the error will average over multiple fill ups. Also more gas you put, less percentage-wise error will be, good luck.