That a great site going to check mine.

Now up to 51.6mpg after a run to Cowdenbeath stock cars last night

For the numpties who can't figure litres into gallons > converter

By far the best way you "should" be checking your mpg is to fill the tank up till the fuel stops filling, drive the car then refill the car again, then you can work out your fuel consumption. Don't assume cause your on board computer says your getting 45 mpg you ARE getting 45 mpg.

ok so I am a numptie, but when you say fill the tank till it clicks off, then drive the car and then refill - how far should I drive the car? round the block, 1 mile, 10 miles 200 miles? lol

I'm a numpty and I'm going to try and think logically. You can do 10 miles say when the tank is full. Then fill up the tank again and see how much petrol you have to put in to make the tank full again. Then you would know how many miles per gallon you have done. Is that right? Or more like litres per mile?

my dad borrowed my car for work the other week (1.25 mk 4 fiesta zetec) and got 60mpg out of it on a long run on dual carriageways and around 40ish driving normally which is more than i get when i drive it. i think i'm gonna have to be a bit nicer to it and change gears earlier to get it up cos petrols expensive :(

How I work out mpg I fill the tank till the pump stops, reset the trip counter drive till half tank or nearly empty then go back to the same petrol station and same pump and fill up till the pump stops, take a note of the litres used and miles travelled on the trip counter. Divides litres used by 4.545 and divides this by the miles travelled

e.g. 45litres divided by 4.545 = 9.90 gallons

400 miles divided by 9.90 gallons = 40.4 mpg.

To be truthful, I don't care how many miles I gallon I get I JUST WANT MY CAR NOW!!

Won't be long now jma78b.

Wouldn't just go out and get new sensors fitted without them being checked first! MPG all depends on what sort of journeys are you doing ( short/long/in town/motorway/starts-stops....), road conditions, weight in the vehicle, do you drive with windows open, do you drive with air con on. Lots of factors effect mpg. The open windows effect your drag, air con puts strain on engine components meaning more fuel is used, so it's a never ending list of things.

air con effect on mpg

better mileage and how to achieve it <- ignore the fact it's an american site. the facts are the same for any car

My engine warning light has beeb on for a few weeks now, and when run on the diagnostic computer it's because of a fault on my Lambda....but the guy told me if was because i fill up at tesco....!!it's gone to my usual mechanic today (not the one who told me that my engine warning light was on because i get my fuel from tesco....!!) so hoping he will be able to sort the problem out. My MPG has always been the same, no matter where i've driven, how i've driven, whether i've been on the motorway the whole way or if i've been driving to work...the fuel light always come on at 290ish (give or take 2 or 3 miles.)

My engine warning light has beeb on for a few weeks now, and when run on the diagnostic computer it's because of a fault on my Lambda....but the guy told me if was because i fill up at tesco....!!it's gone to my usual mechanic today (not the one who told me that my engine warning light was on because i get my fuel from tesco....!!) so hoping he will be able to sort the problem out. My MPG has always been the same, no matter where i've driven, how i've driven, whether i've been on the motorway the whole way or if i've been driving to work...the fuel light always come on at 290ish (give or take 2 or 3 miles.)

Tesco fuel being inferior is an urban myth. I've run cars for years on the stuff with no problems.

My wife used to work at the Grangemouth refinery - all tankers filled up from the same pipeline.

ok so I am a numptie, but when you say fill the tank till it clicks off, then drive the car and then refill - how far should I drive the car? round the block, 1 mile, 10 miles 200 miles? lol

Well when i said fill the tank then drive it then refill it, the OBVIOUS answer is TILL IT NEEDS REFILLED! No one can say they are getting a certain mpg until you've actually driven a decent distance. Driving 28 miles then saying you`ve managed 45 mpg isn't a proper test, and neither is using the on board computer as it's obviously not accurate enough as people are finding out. The further you actually drive the better and more real an mpg figure you will get.

( it's not rocket science )

How I work out mpg I fill the tank till the pump stops, reset the trip counter drive till half tank or nearly empty then go back to the same petrol station and same pump and fill up till the pump stops, take a note of the litres used and miles travelled on the trip counter. Divides litres used by 4.545 and divides this by the miles travelled

e.g. 45litres divided by 4.545 = 9.90 gallons

400 miles divided by 9.90 gallons = 40.4 mpg.

Thank god, someone with sence at last. Gold star for you :)

Sorry for asking

Feel like a &#33;Removed&#33; naughty kid now - shall I go sit on the stair!

How rude!

Michelle - I didnt understand either !Glad it wasnt just me!

Dont think that was the nicest way of answer a question. I didnt know how to work it out probably either so thanks for the help!

I still don't get it *puts on dunces hat and sits in corner playing with her toes*

Have you tried working out the MPG yourself? I've found my trip computer is a bit out. That says I'm averaging around 48 mpg but I actually get closer to 54 mpg. My car's done around 3000 miles (1.6 TDCi) so I expect this to improve in time.

Just collected te new car yesterday and drove 200 miles home. driving between 60mph and 80mph. The trip computer says exactly 50.0 mpg. Does that mean I am getting more?. surely not. I have yet to do a brim to brim calculation.

Can we see a pic of your new car. Fancy a drool. :)

Just collected te new car yesterday and drove 200 miles home. driving between 60mph and 80mph. The trip computer says exactly 50.0 mpg. Does that mean I am getting more?. surely not. I have yet to do a brim to brim calculation.

Probably not, my fiesta started off saying 41mpg. Try resetting it or calculating (explanation above if your dim like me and didnt get it) :)

No point filling the car up till it almost leaks out of the fuel cap, if you use the same pump and petrol station it should in theory stop at the same point.

For you guys who are still having problems I’ve just calculated mine again :)

How this works is with the car full of fuel and the trip counter reading 000, I have been driving till nearly empty, the trip counter reads on my car 434 miles so I went back to the petrol station and fill up again, which took 36.46 litres of fuel.

So because the car was full before I started this would mean that the fuel used in the tank can be calculated to give the almost correct mpg because when I went back and filled up I know that on 36.46 litres of fuel I travel 434 miles,

So 36.46 divided by 4.545 = 8.022 gallons

434 divided by 8.022 gallons = 54.10 mpg.

Hope this helps guys

Sara.

By the way I learnt this from my dear old dad as he was always working his out,

RIP Pops :)

Thankyou Sara, I will try this next time I fill a full tank.

No problem Michelle and like you when hubby drives it, I get no where near that figure. :)

Tesco fuel being inferior is an urban myth. I've run cars for years on the stuff with no problems.

My wife used to work at the Grangemouth refinery - all tankers filled up from the same pipeline.

That's exactly what i said, but my mum and dad were convinced everything he said was sacred....!!!

Anyway, it's fixed now, i've not driven far enough to feel the benefits yet though, i will report back!