LPG (Autogas): does it really save you money?
Autogas sells for roughly half the price of petrol at the pump, which sounds like an easy win. The real sum is not that simple: you burn more of it, the conversion costs money, and you have to find it. Here is when LPG genuinely pays off, and when it does not.
What Autogas actually is
LPG, sold for cars as Autogas, is liquefied petroleum gas, the same family as the gas in a home cylinder. A converted petrol car runs on it through a second fuel system, keeping the petrol tank as a backup, so you switch between the two. At the pump, LPG is usually far cheaper per litre than petrol or diesel.
That headline price is why people assume it halves their fuel bill. It helps, but the number on the pump is not the number in your pocket.
The catch: you burn more of it
How much cheaper LPG is, per litre
Against petrol, in the 19 EU countries that report an LPG price. Shown at full strength: the countries Fillz covers.
median country
a reported price
for the same distance
European Commission, Weekly Oil Bulletin, week of 2026-08-31
LPG carries less energy per litre than petrol, so the engine uses more litres to cover the same distance, commonly in the region of 15 to 25 percent more. That extra consumption eats part of the per-litre saving. You still usually pay less per kilometre, but nothing like the half-price the pump suggests.
The honest way to compare is cost per 100 km, not per litre: the LPG price times how many litres your converted car uses to travel 100 km, against the petrol equivalent.
The conversion, and who it pays off for
Converting a petrol car to LPG costs a meaningful sum up front. You only get it back once the per-kilometre saving has added up to more than you paid, which depends entirely on how far you drive. A high-mileage driver can recoup a conversion in a year or two; someone doing modest annual mileage might never break even before changing cars.
Worth considering for high-mileage petrol cars kept for years, and for drivers who mostly do longer runs. Rarely worth it for low annual mileage, for a car you plan to change soon, or for diesels, which are not the usual candidates for conversion.
The practical hurdle: finding it
LPG stations are far sparser than petrol and diesel, so running on Autogas means planning where to fill rather than pulling into whatever is nearest. You also give up some boot space to the tank, and prices between the stations that do sell it still vary.
This is exactly where a map that shows LPG per station earns its place. Fillz lists the stations near you that sell Autogas, with their prices, so the sparser network stops being a guessing game.
Common questions
Is LPG really half the price of petrol?
At the pump, often close. Per kilometre the saving is smaller, because the engine burns more litres of LPG. Compare cost per 100 km, not per litre.
Does running on LPG harm the engine?
A good, properly fitted and maintained conversion runs cleanly. The key is quality installation and keeping up with the servicing the system needs.
How long to earn back the conversion?
It depends on your mileage. Divide the conversion cost by your saving per kilometre. High-mileage drivers recoup it quickly; low-mileage drivers may not before selling the car.
Can any petrol car be converted?
Most modern petrol engines can, but suitability varies by car, and it should be done by a qualified installer. Diesels are generally not converted this way.
Do the per-kilometre sum, then find the pump
Autogas can be a real saving for the right driver, once you count consumption and the conversion. When it stacks up, Fillz shows you which stations nearby sell LPG and for how much.
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