Fuelly computing the wrong MPG... and it's intentional...?

[JockoT]

If I fill up with 97 RON I don't know what mpg I get until the next time I top up. The mpg calculated is always the fuel used the top up before. As Draigflag says, only the volume of fuel is used in the calculation.

[spiceygas]

Originally Posted by JockoT

If I fill up with 97 RON I don't know what mpg I get until the next time I top up. The mpg calculated is always the fuel used the top up before. As Draigflag says, only the volume of fuel is used in the calculation.

What I'm saying is that it's attributed to the wrong octane. It's great that the volume is used and therefore the correct division is computed, but the correlation with octane is completely wrong.

In the bar chart on the first thread post, Fuelly shows a computed MPG for 93 octane fuel even though no 93 octane fuel had ever been driven through the engine.

Octane <==> MPG correlations are not computed correctly.

Originally Posted by Draigflag

I hear you, what you're saying is, when you fuel up on fuelly, you're inputting the octane and price of the fuel you just put in, but the volume is essentially the fuel you just used.

No.

The issue is not one of arithmetic. It's that the attribution to octane rating is wrong.