Fuelly Calculations wrong? :S

[Ziggy122]

Right - i keep working it out differently to how fuelly does

I did 362 Miles on the last tank
Used the 43 litres i put in
43 litres = 9.45867377 Gallons (9.46 to 2DP)
So 362 / 9.46 = 38.2mpg

So why does fuelly say 37Mpg?

i've checked the figures - there all correct :S
So what am i missing or is that adding?

Ziggy

 

[Eklipze3k]

So you've done 362 miles since the last time you filled up and you put exactly 43 litres in this time? I'd say your maths is right, I've always been a bit dubious about Fuelly's figures tbh ...

Edit: Just looked at your Fuelly page, it says you put in 44.441 litres so that's why it's different

Edit2: I think you're looking at the wrong fuel input - you're basing your calculation on the initial amount of fuel you put in and the 362 miles you've done since then but that's not how much fuel you've used to do the 362 miles, it's the amount you've put back in since doing the miles is how much has been used.

 

[Ziggy122]

I was working out my average MPG on the tank i've just finished not what 've put in
Which was 362 and 43 litres

Edit - Doh - yea i did average 38 on the tank using the figures i've said - but as you've said its using the 44.440 not the 43
its a average guide anyway just show how short runs dont help a MPG figure


Ziggy

 

[sludgeguts]

The fuelly thing isn't a good guage anyhoo.
When I took my magnets off to start this experiment, I was running on just diesel - averaging 38mpg per fill.
Since I started adding veg oil I noticed was getting better results, around 41mpg but my fuelly banner is showing less because it is also including the old averages.
It would be better if it showed current average mpg (say from last couple of fills) or simply say "last mpg", as well as overall average

 

[Eklipze3k]

You can force it to do that by deleting old fuel ups