Is an LPG conversion worth it? Work out your payback
LPG costs about half of petrol per litre, but the conversion has a cost and the car consumes a bit more. The real question is one: how many kilometres it takes to recoup the spend. This calculator answers it with today’s real prices — edit them with yours.
Today in Italy: self-service petrol €1,953/L · LPG €0,799/L (Osservaprezzi Carburanti — MIMIT, 2026-05-29).
Calculate your payback
Pre-filled with the latest MIMIT data, editable.
When LPG really pays off
LPG’s value depends almost entirely on how much you drive. The more you drive, the sooner you amortise the conversion: 20-30,000 km a year pays back in little over a year, 5,000 km can take several years. So the figure that matters isn’t “how much I save per litre”, but “how many km to recoup the investment”.
Two things lower the theoretical saving: on LPG the car consumes about 10-20% more (a litre of LPG yields less than a litre of petrol), and the conversion must be factored in (typically €1,500-2,000 for a compatible petrol car). The calculator accounts for both.
Also consider: the tank takes boot space (or replaces the spare wheel), needs periodic inspection (replaced every 10 years), and some areas or underground car parks have restrictions. Over the long run, for high-mileage drivers, the saving stays clearly positive.
Frequently asked questions
Is LPG worth it in 2026?
Yes for medium-high mileage. At today’s prices (petrol €1,953/L, LPG €0,799/L) a typical conversion pays back in roughly 1-2 years for someone driving 15-20,000 km a year. Below ~8,000 km a year it takes much longer.
How much do you save with LPG vs petrol?
Per kilometre, roughly half: LPG costs about half per litre, and even accounting for ~15% higher consumption the cost per km is well below petrol. The catch is the upfront conversion cost.
How often must the LPG system be inspected?
The tank must be replaced every 10 years (by law), with periodic checks in between. Budget this in the long-term maths, though it’s a small cost spread over a decade.