We need to know how much gasoline cost we're incurring per trip for logistics, but we need to run experiments on how much gasoline is used for every unit of distance. (e.g. 15L/mile), but the issue, is the gauge we have is something like this:

enter image description here

We know how much gasoline we load in because gas stations have metrics, but how much of that is used is a little hard to get. With a gauge as shown in the image, the only way I can think of is to measure the length of the arc that increased after gasoline was pumped in the truck, then measure the length of the arc after the trip and then subtract the initial length to the length after the trip then use ratio and proportion to actually get how much gasoline was used for the trip.

Then I can also get the gasoline per liter by [Gasoline Used in Trip/(End Mileage - Start Mileage)]

I am wondering how accurate these gauges are and if my methods of ratio and proportion will work. I am also wondering if there are any tools to actually digitally show how much gas is used?

1 Answer 1


Best way is to record the actual mileage on the receipt as you pay for the fuel : then from the past receipts you have distance per tank and cumulative and the exact volumes of fuel.

Just calculation from there.

The gauge is an “indicator” ie not precise, not always linear so the indication of quarter tanks can be “off”, mostly due to the shape of the tank which may not be a constant cross-section and also affected by the “sloshing” of the fuel.

  • I'm not quite sure I understand so I just need 2 metrics if i'm not mistaken? 1.) Distance traveled between gas refills and 2.) Volume of gas loaded on refill ? Then as the sample size increase, I can estimate the distance/unit of my truck? Because the tank will not be fully used up on 99% of the cases and have some leftover prior to any refill
    – Pherdindy
    Oct 15, 2018 at 6:09
  • The distance travelled is based on the volume necessary to refill the tank... As the tank will not be fully empty etc. Unless you want to use the "top Gear" method ie fill the tank to the brim and drive until the engine dies... Then you have the exact volume and the exact distance - as long as you don't roll a long distance as you stop...
    – Solar Mike
    Oct 15, 2018 at 7:15
  • Thanks.That makes sense. One last thing is there a risk to full tanks? I heard some people say it's not good to fill up the tank due to expansions caused by heat
    – Pherdindy
    Oct 15, 2018 at 7:31
  • If you leave the neck empty should be fine...the volume expansion coefficient of petrol is about 0.001 per degree C so 1 millilitre per litre per degree C... You will probably find slosh and loose fitting caps are more of an issue...
    – Solar Mike
    Oct 15, 2018 at 7:36
  • I see but how will sloshing of gasoline become an issue assuming the caps are working as they should?
    – Pherdindy
    Oct 15, 2018 at 7:44

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