What was my mpg ??

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Hi

I want to work out my mpg for a rather large journey i went on yesterday.

I drove 404 miles
Filled up twice, the first time i filled up with £27 and the second time i filled up with £19.50.

At both times the petrol cost 84.9 pence.

I did motorway driving (trekking up and down the M1).

When i left my house i had quarter of a tank of petrol and when i returned i had the same.

I've tried some of those online mpg calculators but they say i've been doing 47 miles to the gallon which can't be true because according to my owners manual it does 35mpg!

Thanks
 
Man of Honour
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Ignore all these figures as they are inaccurate. You cannot accurate calculate fuel consumption by saying you had a quarter of a tank when you left and a quarter when you got there - your fuel guage is not a calibrated instruement and is notoriously inaccuate.

The way to do it is to brim the tank, reset the trip counter, drive, then brim the tank again. This will then tell you exactly how much fuel was used to cover the distance you covered.
 
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[TW]Fox said:
Ignore all these figures as they are inaccurate. You cannot accurate calculate fuel consumption by saying you had a quarter of a tank when you left and a quarter when you got there - your fuel guage is not a calibrated instruement and is notoriously inaccuate.

The way to do it is to brim the tank, reset the trip counter, drive, then brim the tank again. This will then tell you exactly how much fuel was used to cover the distance you covered.

I know that it wont be 100% accurate but surely a fuel gauge cant be far off.

With the 33mpg fuel consumption im very happy. I'm sure i was probably getting around 30mpg (taking into account what fox has said) because i wasnt exactly driving in a fuel efficient fashion!
 
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Del Lardo said:
33.5mpg


27+19.5=£46.50/0.849=54.77litres*0.22=12.05gallons

404miles/12.05gallons=33.53mpg

I thought i was 4.54 miles to a gallon :confused:

(i may be getting imperial and US gallons mixed up though :o )
 
Associate
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To avoid confusion here i am not asking for an exact figure for my fuel consumption.

Just a rough sort of estimation so i know roughly how many miles per gallon i was doing.

I know the fuel gauge isnt 100% accurate but it can't be THAT far off. Or can they??
 
Caporegime
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the number of times my trip computer has told me i have 0 miles remaining is quite humerous !

but admittedly i would probably only get another 10 miles or so max out of the tank at this point, being on the last bar of the electronic fuel guage.
 
Associate
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I make it roughly 33.53 mpg.

£27+£19.50 = £46.50

£46.50/.849 = 54.77 litres

404 miles/54.77 = 7.37 litres x 4.54 (uk gallon) = 33.53

But yeah you need to brim the tank drive for a couple hundred miles then brim again.
 
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