Tankful
Enter your car's fuel consumption, how far you drive in a year and what the LPG conversion costs. The calculator works out how much you save on autogas compared with petrol and how soon the system pays for itself. Fuel prices are filled in with Polish averages from 28 September 2026, converted to euro: petrol €1.54/l, LPG €0.75/l.
How to use the calculator
- Kilometres a year – how far you drive in a year. This matters most: the more you drive, the faster the system pays off.
- Petrol use – your car's average consumption. If you don't know it, work it out with the fuel consumption calculator.
- LPG use – a car usually burns 15–25% more LPG than petrol. The calculator fills in 20% more, but you can change it.
- Fuel prices – Polish averages by default. Enter the prices at your station for a more accurate result.
- Conversion cost – a sequential system, fitted, usually costs €800–1,300 in Poland and more in Western Europe. Direct-injection engines cost noticeably more.
- LPG servicing – system inspections, filter changes and any extra roadworthiness tests. The calculator subtracts this from the yearly saving.
How much you save on LPG a year
The saving before servicing costs, at today's Polish prices and with LPG use 20% higher than petrol:
| Kilometres a year | 6 l/100 km | 8 l/100 km | 10 l/100 km |
|---|---|---|---|
| 10,000 km | €388 | €517 | €646 |
| 15,000 km | €581 | €775 | €969 |
| 25,000 km | €969 | €1,292 | €1,615 |
| 40,000 km | €1,550 | €2,067 | €2,584 |
Who LPG makes sense for, why it burns more and what to keep in mind before converting – read Is LPG worth it. Cost a specific trip on LPG in the Tankful calculator.