I know you shouldn't take the distance to empty reading as gospel but yesterday my car said it had 40 miles to empty, so I put £15 in around 14lts and the car then said it had 148 miles remaining I drove 2 miles home then today I started the car and it was saying 98 miles remaining :/

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It works it out based on your driving! If you are driving 'enthusiastically' then you get less mpg! Drive more economically and the mpg goes up!

I was thinking the same thing...surely my car mileage doesn't equate to the petrol mileage?

nah its basically several factors taken into account:

> Current Live MPG

> Overall average MPG

> Temperature

> Reported Fuel Level

It basically calculates in essence two values adds them and divides them by two (to my knowledge). So for arguments sake have a look at this example:

Current MPG: 55

Average MPG: 50

Current Gallons in tank: 10

Miles Per Gallon: (550x10) = 550 (live MPG) + (50x10) = 500 (over the course of the live readout) = 1050 / 2 = 525 miles to empty.

Whereas lets say you were now driving with a heavy foot:

Current MPG: 20

Average MPG: 50

Current Gallons in tank: 10

Miles Per Gallon: (20x10) = 200 (Live MPG) + (50x10) = 500 (Average MPG) = 700 /2 = 350 Miles to empty.

This is why the numbers can fluctuate so wildly, because you have to balance the live and the average to a good high number before you get the best back, and why even if you only put your foot down for a few minutes, you can lose pretty much half of your estimated range.