New user, confusion...
 

Hey, I'm new on fuelly, having just bought a new car, and I am having a strange confusion with how this works...

When I got the car, I put in £30/22.5l of petrol, and drove about 180 miles.
I then put in another £30/22.5l of petrol, and then on fuelly I entered the following details:
"distance 180 miles, 22.5litres of fuel"

Today, after another 185miles, I went and actually filled up my tank to the brim (39.14litres). I went into fuelly and entered:
distance since last fuelup - 185miles
amount of fuel - 39.14 litres

...and it comes up with a fuel economy of 26mpg. Which is incorrect, because what I had actually done was 185miles on 22 litres, not 185miles on 39 litres which seems to be what it is calculating from.

Am I supposed to wait until the tank is empty again, and enter that mileage figure into fuelly with the "39..14litres" figure?

You've been 530 miles on 84.14 litres, that's 28.6mpg. So fuelly's mpg figure is correct.

I'm not sure about your 180, 180, 170 miles, that doesn't sound very accurate...

Well no, cos the car was empty of fuel when I got it, so that first fillup should be 0 miles... but it doesnt let me put zero miles as a number. Seems like fuelly should have a different page setup for the first every fuel stop.

So when I stop for petrol, I should write down how much fuel I put in the tank, and record the number of miles I did on the *previous* tank of fuel?

What figure should I put in as miles driven for the first fillup I do though, when there is no figure for miles driven? IT does not allow zero

Plus that was 530 miles on 45 litres, as the car hasnt used any of that 39.14 litres I just put in yet. Its still in the tank.

You only know how much fuel you've used once its gone and you've refueled. Best thing to do is fill the tank for the first time, use the fuel (some of it or all of it, up to you) then refill the tank. Only then do you know how much fuel has been used for the miles you've travelled.

Get it?

Oh yea, it asks for "litres used" not "litres you've just put in and you're about to use"

oh i seee... so when it says to "add a fuel up", I'd thought it meant to enter the details of the fuel up I just did... not my previous fuel up!

This makes more sense in the long run I guess, though it does mean keeping track of previous receipts until I next fill up, so I can enter the right details.

No problem though, thanks for that, I'll correct my entries.

It calculates the fuel you've just used over the miles you've just done. No need to keep reciepts or anything. I tend to look at the pump as I get back in the car. Then on my phone I write the litres ive just put in (has to be brimmed to do it properly) and the miles I travelled. Then I reset the oddometer to see how far the next tank will go, and repeat! Then I get home and put them in fuelly of course :)

Why is this so hard. Each time you add fuel you enter the odometer reading and the amount of fuel you put in. Then if you did not completey fill the tank check the "partial" box. That is it.

There is no need to figure out how much fuel you used or miles driven.

I can understand why this is confusing; I've made a post about this elsewhere as a suggestion. The way Fuelly displays its per-fillup MPG is to list the figure next to the next fuel-up, rather than next to the fuel-up that yielded the MPG. I believe it should be the other way, but it's not a crucial difference once you're used to it.