The great "unknown" between gasoline and electric cars: autogas makes the tank cheaper and grants an eco label for driving in the city

News such as that the CPI closed September at 4.9%, largely due to the escalation in gasoline prices, has an unexpected effect in a workshop in Getafe. This has been happening for years every time information about how expensive gasoline or diesel is appears in the media. Vehicle owners call and Nacho Pérez, owner of a "reference" workshop in the transformation of gasoline cars so that they can also circulate with autogas, the LPG variant applied to mobility, picks up the phone, which reduces the cost of filling the tank by 40% and, depending on age, provides cars that did not previously have it with the eco label that allows them to circulate in low-emission areas in city centers.

"We do not have a seasonal market, it is constant, but demand is conditioned by the price of fuel. When there is a rise like now, daily calls skyrocket. As soon as there is news of the price increase, we notice it a lot," explains Pérez, who runs a workshop that has been hybridizing cars for 52 years to add a tank to the gasoline or diesel tank, for autogas. He started doing it to taxis, because until several decades ago only they were allowed to use this fuel. When it was possible, driving schools also began to take an interest in it, also seeking the savings it entailed. One of the last great milestones came in 2016, when the system that classifies different vehicles based on what they pollute was created and the labels were created, more in the mouths of drivers as a result of the creation of low-emission zones in the center of cities, which can only be accessed with an eco label.

Autogas is what Liquefied Petroleum Gas (LPG) is called in mobility. It is still a fossil fuel but emits fewer polluting particles and 20% CO2 emissions. It is not the solution to fight global warming, but, closer to home, it is less polluting enough to be fiscally classified as ECO and allowed access to ZBEs such as electric cars. In economic terms, the driver saves around one euro per liter if he refuels with autogas instead of gasoline. Although less, it is also cheaper than diesel.

"It is one more way to decarbonize," they say from Repsol, which has been betting on autogas for years, with packages to make the change easier for its customers, alliances with the largest vehicle manufacturer of this technology, Renault, or with discount vouchers to encourage them to switch to fuel. Gasib, the company that acquired the LPG assets of the former Cepsa (now Moeve), is also clear about its bet. In the same way that the new owner has decided to abandon channeled LPG for the residential sector, Gasib is clear about its commitment to LPG for the automotive sector, autogas. "It is a practical solution that allows people to live their lives as before without changing their habits too much," says GASIB CEO, Filipe Henriques. As with Repsol, it states that autogas provides "benefits for everyone", economically and also ecologically, which will become more so as the production of biodiesel and sustainable aviation fuels (SAF) grows, from which biopropane is directly derived, which will be compatible with autogas engines.

Despite its advantages, these two companies point out the "great lack of knowledge" that exists about a fuel that is a good alternative to gasoline due to price and emissions. It is also true for the electric car for different reasons, because in the case of autogas the necessary investment is lower to begin to have savings in fuel and access to ZBEs and compared to electric charging points, it has a greater network of places to refuel. Repsol alone has a network of 500 gas stations, also with autogas pumps, which are completed with a thousand in total, also those provided by the Moeve gas stations.

"Another thing is ignorance," agrees Pérez, who is also vice president of the Association of Vehicle Transformers (ASTRAVE). While in Italy and Eastern European countries autogas is the order of the day, the data in Spain is modest, although constantly growing in recent years. In the absence of consolidated data for 2025, in 2024 5,200 conversions of vehicles to autogas were carried out, growing by 29.6% compared to 2023, according to ASTRAVE. In the case of new vehicles, 4.42% of the vehicles that were registered last year were autogas, 60,580 cars, 72.4% more than in 2024, according to the Spanish Association of Automobile and Truck Manufacturers (ANFAC). Until now, Renault has been the major manufacturer in autogas, because more than 80% of this type of vehicles have been produced from its plants, but the sector also recognizes the "boom" that Dacia and its Sendero model has experienced, which last year saw more registrations in autogas than in gasoline or diesel.

Taxi drivers are now taken over by VTC drivers, who seek to reduce the cost of refueling. Outside the professional sphere, Pérez explains that in his workshop they have various types of clients, although sometimes they combine. "There are those who only look for the ECO label. They are small cars, normally second vehicles for which consumption is not as much as having the label" to be able to enter the ZBE. "And then the one that doesn't look for both the eco label and savings. Normally they are much larger cars, like SUVs, with which their owners drive many kilometers."

In either case or in both at the same time, the result is a car with two tanks, one for the original fuel and the other for autogas, except when starting, it will run until it runs out and has to return to gasoline or diesel if it is not refilled. Filling the autogas tank costs around 40% less than gasoline - approximately one euro less per liter - which means that autogas consumes between 10% and 20% more than gasoline. With it you can also circulate within restricted areas.

The conversion of a gasoline car is relatively quick and cheap. It depends on the model, but from his workshop in Getafe, Pérez indicates that "for a normal car", the price is around 1,400 euros, which with VAT remains at 1,700 or 1,800 euros. It takes a week to make the change and they are delivered "approved" and with the registration change procedure and with an ECO label that also reduces the Tax on Mechanical Traction Vehicles (IVTM) by 75%.

Most of the cars that pass through Pérez's workshop are between three and seven years old, although he usually works with older vehicles. The limit is that it be 25 years old because the transformation cannot be done to cars from before 2001. Those registered before 2014 will not obtain the eco label either and their advantage will only be economic. "And that the car is good. If the car goes bad, it will go bad," he adds.

Mostly light vehicles and, at most, vans pass through its workshop, despite the fact that another of Gasib's bets is to implement autogas in heavy transport, in trucks, as an alternative to renewable gases that still do not have an implementation that allows them to completely replace gasoline or diesel.

In this case, the transformation consists of replacing the engine and for this there is a Spanish start-up, BeGas, which manufactures autogas engines, recognized by the Center for Technological Development and Innovation of the Ministry of Science as a Strategic Company and whose shareholding Gasib entered in June as the third largest shareholder, precisely, to promote the autogas business in heavy vehicles.

At the moment, however, in the professional transport sector it has not finished "consolidating" and continues to rely instead on renewable fuels, according to the Spanish Confederation of Freight Transport (CETM), who point out two main reasons why autogas has not yet 'taken off'. On the one hand, because, although cheaper, autogas has also risen since the war in Ukraine, which made it "less attractive." Secondly, because breakdowns with this technology have a more complicated repair and there are fewer workshops for it.