Disappointing fuel economy plus fuel tank size

sebdangerfield

Yes that's totally right now, the fuel guage is more accurate at zero that a quarter.

Well done on the sums.

skiddlydiddly

They are saying remove all chance of an inaccurate fuel guage by using the calibrated fuel pump in your local petrol station when you fill up.If you use the same pump between fillups it removes even more inconsitancy.

1.Fill up your tank to the brim-you can see the petrol in the top of the filler pipe.
2.Drive say 200 miles
3.Fill up again to the brim.
4.Check how many litres you have used and divide it by 4.54(something like that) to get gallons used
5.Divide 200 by how many gallons used.You now have a very accurate figure for your mpg.

It doesn't matter if your fuel guage is accurate/innacurate/doesn't work with this method as you remove it form the equation.

cyclonebri1

thor wrote: »

It is not a wind up, honest.
I am being told to forget the gauge but then also to fill up when the meter is showing empty.

I don't believe you, well I do to be honest.

What has escaped you is that NO ONE has said fill up when empty, just when you have used "most" of the fuel

LandyAndy

cyclonebri1 wrote: »

You do not need to start with an empty tank, but the lower it is, the more accurate the result. Note the mileage, brim it, drive, when nearly empty do the same again and use the fuel used to brim it a second time to work out for used for your driven mileage:eek:, I've just realised you might just be winding us all up.

Forget the Goddam guage, :T

cyclonebri1 wrote: »

I don't believe you, well I do to be honest.

What has escaped you is that NO ONE has said fill up when empty, just when you have used "most" of the fuel

It doesn't matter how much is in the tank for the first fill up. Your first post suggests otherwise.

LandyAndy

LandyAndy wrote: »

As I said in my first post, you don't grasp what is required.

Imagine you have no fuel guage.

There are only two states that you can be sure of, full and empty.

We are going to work with full.

Fill the tank to, say, the second click of the pump. You don't need to know how much you've put in.

Zero the trip counter. Drive for some miles, say about 300.

Now fill the tank in the same way again and note the amount of fuel put in.

You now know exactly how much fuel you have used to cover the 300 or so miles and you haven't needed a fuel guage or to know how big the tank is.

skiddlydiddly wrote: »

They are saying remove all chance of an inaccurate fuel guage by using the calibrated fuel pump in your local petrol station when you fill up.If you use the same pump between fillups it removes even more inconsitancy.

1.Fill up your tank to the brim-you can see the petrol in the top of the filler pipe.
2.Drive say 200 miles
3.Fill up again to the brim.
4.Check how many litres you have used and divide it by 4.54(something like that) to get gallons used
5.Divide 200 by how many gallons used.You now have a very accurate figure for your mpg.

It doesn't matter if your fuel guage is accurate/innacurate/doesn't work with this method as you remove it form the equation.

How hard are these instructions to understand?:(

Inactive

LandyAndy wrote: »

How hard are these instructions to understand?:(

Very, it would seem, I admire your patience, me...I'm out of this thread before I do myself some harm, I cannot continue to bang my head against this wall..

cyclonebri1

LandyAndy wrote: »

It doesn't matter how much is in the tank for the first fill up. Your first post suggests otherwise.

mere slip of the tongue my boy;)

You know the best part of all this, nothing Thor does apart from modifying his driving technique will make a knats worth of difference to his fuel consumption :rotfl::rotfl:

kaya

you cannot accuratly work out fuel consumption by volume and a cheap fuel gauge supplied with the car, the only accurate way is by measuring the carbon in the exhaust and comparing it to the carbon in the fuel you use or by weight, the volume of fuel changes with temperature, you can draw it from the underground storage tank via the fuel pump and it may be at 2 or 3 degC, you put it in your fuel tank and at some point it reaches ambient temperature of between 10 and 20 degC which could equate to a 10% increase in volume, so you put 50l in , park it in the sun for a while and you have 55l , figures are approx guestimates but im sure you get the idea, the toyota prius was quoted at a rediculous mpg figure which was unachievable by normal driving, the us government changed the test criteria one year and it knocked 10mpg off of the manufacturers claimed mpg figure's for the car, if you cant afford to put fuel in your car then go buy one with a smaller engine

vikingaero

kaya wrote: »

you cannot accuratly work out fuel consumption by volume and a cheap fuel gauge supplied with the car, the only accurate way is by measuring the carbon in the exhaust and comparing it to the carbon in the fuel you use or by weight, the volume of fuel changes with temperature, you can draw it from the underground storage tank via the fuel pump and it may be at 2 or 3 degC, you put it in your fuel tank and at some point it reaches ambient temperature of between 10 and 20 degC which could equate to a 10% increase in volume, so you put 50l in , park it in the sun for a while and you have 55l , figures are approx guestimates but im sure you get the idea, the toyota prius was quoted at a rediculous mpg figure which was unachievable by normal driving, the us government changed the test criteria one year and it knocked 10mpg off of the manufacturers claimed mpg figure's for the car, if you cant afford to put fuel in your car then go buy one with a smaller engine

That's handy to know that I need to carry a rig clamped to my exhaust to accurately measure fuel consumption. I think I'll stick to the tried and tested method of brimming and mathematics.:D

skiddlydiddly

Kaya are you having a laugh?

Assuming the absence of thermostaticly compensating carbon measuring equipment(lets call it TCCME), lets just do it the way anyone who doesn't look like Beaker from the muppets or one of the Teefal boffins would eh?