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Guys,

I am in a lookout for different ways to measure fuel efficiency.
Please let me know how can I get the most correct Fuel efficiency measured.

Thanks.

Under what conditions? Altitude? load? type of engine? vehicle? ambient temperature?

You have access to an engine test bed? That would be your best bet.

Thats too technical for me. I own a i10 era.

I usually top the tank up and set the tripmeter to zero. When the tank is nearing empty, I fill it up again. So, If I divide the no of kms run by the no of liters filled (the second time), I should be able to get the average consumption.

Or you could get a car like a punto or a Linea which has a Multi Info display screen which shows average fuel consumption on a real time basis:D

One thing here is to make sure that, at both times, the petrol pump chap doesn't fill the fuel beyond when it automatically stops.

i have serious doubt about this. B'coz i had taken the delivery of Punto 1.4 petrol for my sister from concord motors. But the average was showing 26 kmpl :Shockked: in trip A and trip B was showing avgerage of 18.9 kmpl.

This is what I read at one of the MASS regarding the best way of measuring FE:

1. Fill tankful fuel.
2. On empty, fill fuel from the same pump and preferably from the same nozzle.

Then apply the formula that addyhemmige is suggesting.

This approach of refilling up from the same pump and from the same nozzle will take care of the measurement variances between various pumps and nozzles.

Cheers,

For me, its always been like below which is like bible for me to check on my FE :

Fuel Tank Capacity : 45 Litres
Low fuel warning lamp comes up at 37 Litres of completion.

I tank up immediately ( it always comes to 37 Litres with auto-cut off) and set the trip meter to 0.

When i get the low fuel warning lamp. I do this :-

No. of Kms Driven/37 Litres = My Perfect FE:thumbs up

As per your suggestions. My car does not have a trip meter. So what do I need to do?

Nice way to calculate FE.

For Maruti suzuki vehicles, there is no low fuel warning lamp because....
......''ye maruti suzuki hai, petrol khatam hi nahi hota''.....:D

What? as per your profile, your car is i10 era.

Maruti don't provide low fuel warning lamp, hyundai don't provide trip meter.:D [ as per sidd25 and ye baat hazam nahi hoti ].

:Shockked: Your car doesn't have a trip meter? I thought all cars nowadays have tripmeters.

If you don't have a tripmeter, take a reading of the kms run on your odo meter when you fill up and take the reading again when you fill up the second time. The difference between the 2 readings should give you the kms run:)

There is no perfect way to guage fuel economy (unless you do it in a lab under controlled conditions).

In the real world, a tank up test would be your best bet.

Shan2nu

This is how I calculate mileage after the car comes back from service:

Select a Sunday morning. Fill petrol at my favourite pump. After auto cut off, continue to fill manually up to an inch below the lid of the fuel tank. Wait for a few seconds to see if the tank burps.:) If it does, fill a little more. Note down the quantity, set the trip meter to zero and take the car on a leisurely highway drive for ~ 50 KM round, non-stop trip. Return to the same bunk, same nozzle and fill petrol again as described above. Calculate the FE for the distance covered / fuel consumed.

This gives the "best" mileage possible under the most favourable conditions. Safely knock off 6 - 7 KM from this figure to arrive at the city mileage. Then forget the whole thing for the next 6 months!

EDIT: I do this because I do not use the car daily. If you do, you can easily use the same method to calculate city mileage by filling twice within a gap of 4 - 5 days. BTW does the i10 really come without a trip meter?

which 'era' is your i10 from?
Surprised that it doesn't have a trip meter.
Anyway, in case there really is no trip meter, then when you tank up see the reading in the odo. Then go back to the same pump / same nozzle when your tank is almost empty and tank up again. Get the reading in odo again.
Diff in odo readings / fuel that went in second time gives you your mileage.
Don't tell me that your i10 era doesn't have an odo as well :D

And as far as I know, an i10 era comes with a digital odo (the electronic stuff). It is supposed to have two trip meters as well (I guess), so play around with the dash controls, you might get to see the trip meter readings pop up in the digital odo itself.

I10 not having a trip meter? I am surprised.
Alto has a trip meter - i am almost ready to bet i10 has it. Some cars have only a single line display and don't show the trip meter unless you press that small black button near the ODO. Long press of this button clears the trip meter.