A car that runs on air pressure instead of fuel or electricity – the concept itself is not new. What is new is the idea of the Italian inventor Vito Truglia. Ten years ago he asked himself the question: what if you could convert petrol, diesel and gas engines so that existing cars could run on air?
Much development and partnerships later (including with the Italian branch of TVR, in which Truglia is involved) presents the Dutch SolutionAir today a driving prototype in the form of this Renault van. The principle is simple: instead of moving the pistons in the engine through fuel and ignition, you use compressed air. The van has three gas tanks with a total of 600 liters on board, with which it should be able to drive up to 600 kilometers. ‘To fuel’? That takes, at a special station, about four minutes.
How does it work?
The tanks are filled with air (the aforementioned station can pump up to 1,000 bar; today it holds about 120 bar, enough for a few trips up and down). That air is then fed to the cylinders, but because it is stone cold due to the compression, it is first heated so that the engine does not freeze. This heating also takes place on air pressure.
The engine has changed from a four-stroke to a two-stroke. So air goes out and immediately back in under high pressure, without a compression stroke in between. It only spins about 800 to 1,200 rpm. More is not necessary, because the energy density is much greater when driving on air than on fuel. Truglia’s prototype uses the existing engine and transmission; only the head, crankshaft and piston rings are different, and of course the necessary hardware and software around it. Also valves have been added that equalize the air pressure to allow the piston movement. The turbo? It has disappeared.
How does it drive?
I don’t know, we were only able to be wrong for two minutes. There’s something truck-like about having to shift gears at such low revs. If you want to accelerate faster, the engine will not run faster, but the air pressure will be increased. The technology behind this is still being fine-tuned. The sound is interesting: it pops and rattles a bit, like some sort of hoarse diesel. Check out our Instagram snippet below for an idea.
Will all cars soon run on air?
It is unfortunately not that simple. In principle, relatively modern cars with advanced ECUs should be able to be converted. If someone develops the new parts for their type of engine, that is. It won’t work with your old analog Beetle – so it can remain original and drink synthetic fuel.
Another point is the tank: not all cars have the space of a Renault Master. You can imagine that the place of the gas tank becomes free, but nobody makes gas tanks in such a shape. That too is a matter of supply and demand. It seems that a specially developed tank in an Aygo-sized car should be good for about 100 kilometers of range. So a multiple in larger cars. And hey: if soon there will be sky poles everywhere…
So: is riding on air the future? According to SolutionAir, many large parties think so. Fiat, Renault and Bosch are mentioned as companies that would be interested or already participating in research for new models. Moreover, the technology could not only work for existing passenger cars, but also for commercial vehicles, trucks, even boats and generators. That saves a huge pile of discarded machinery if driving on fuel is no longer possible or allowed. Talk about environmental gain. We will be hearing more about this…