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Fuel Log & Consumption Tracker

Log every fill-up and get your real fuel consumption: L/100 km and mpg between full tanks, cost per kilometre, average fuel price, best and worst tanks and CO₂ — all stored privately on your device.

✔ 100% free Mobile friendly ⚡ No account

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Fill to full, then measure

The only accurate method is the full-to-full one: fill the tank to the top, note the odometer, drive normally, then fill to the top again. The litres you add divided by the kilometres driven give the real consumption. Partial top-ups in between are carried over to the next full tank.

  • Fill the tank to full at each measurement
  • Record the odometer, not the trip meter
  • L/100 km = litres ÷ km × 100
  • MPG (UK) = 282.48 ÷ (L/100 km)

What the numbers really tell you

Consumption alone is only half the story. Cost per kilometre combines consumption and the price you actually paid, and the average price per litre shows whether you are buying at good stations. Watching best and worst tanks reveals how much driving style, season and load change your bill.

  • L/100 km — fuel efficiency
  • Cost per km — the real running cost
  • Average price /L — your fuel-buying habits
  • Best vs worst tank — driving style and season

Why it beats the trip computer

On-board computers are often optimistic by 5 to 15%. A real log uses the actual litres from the pump and the actual kilometres, so it is the only figure you can trust for budgeting, comparing a repair or checking whether a fault (or a new driving route) changed your consumption.

FAQ

Consumption is the fuel burned over a distance. The first full tank only establishes the starting odometer, so the first measured figure comes with the second full fill-up.
Yes. Enter them and untick “filled to full”. Their litres are added to the next full-to-full segment, so nothing is lost.
No. The fuel log is saved in your browser only (localStorage). Clearing your browser data will erase it.
A modern petrol compact uses about 5–7 L/100 km on the motorway and 7–9 in town; a diesel usually does a little better on a run. Compare your own tanks with each other rather than absolute numbers.
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