The Rosmar V-04 has neither a conventional internal combustion engine nor an electric motor. These have been replaced by “revolutionary” technology: short bursts of compressed air propel the rear wheels through a series of precisely calculated “nudges,” causing the car to move. In the future, the developers promise acceleration to 100 km/h in 0.3 seconds (that’s not a typo), but for now, the prototype is only creeping along slowly.
Technical Details
Instead of a conventional internal combustion engine, electric motors, or a traction battery, the design uses compressed-air cylinders. These cylinders act on the rear wheels, causing them to move relative to the body and generating traction.
Currently, the development exists only as a prototype built on the basis of an older Audi model. The creators believe that this system could be particularly useful on slippery surfaces—such as snow, mud, or loose soil. However, before the technology can go into mass production, there are still many technical and engineering issues to be resolved.
The system is based on pneumatic cylinders connected to the rear axle. When compressed air is supplied, they perform sharp reciprocating movements and transfer force to the wheels. Visually, the mechanism’s operation resembles industrial equipment: the wheels not only rotate but also shift noticeably back and forth along special guides.
According to the developers’ design, this principle should allow the vehicle to achieve better traction. On loose or slippery asphalt, a wheel can press more firmly against the ground than with conventional torque transmission via propeller shafts. To a certain extent, this is similar to how an SUV operates, where not only engine power but also the ability to maintain contact with the road is important.
Why is the system installed only at the rear?
To fully implement this system on all four wheels, a large amount of space would be required to accommodate their longitudinal movement. This is particularly challenging on the front axle: the wheels must turn simultaneously to steer the vehicle, and additional movement could seriously affect stability and steering precision.
Therefore, Rosmar H limited the system to the rear axle. Even in this configuration, the wheels extend significantly beyond the normal body dimensions when the mechanism is in operation. For a passenger car, such a design must be covered with special protective elements to eliminate risks to pedestrians, other vehicles, and the driver.
Experience from Previous Projects
The idea of a compressed-air-powered car is not new. One of the most well-known projects was that of the French company MDI, founded by engineer Guy Negre in the early 1990s. It later unveiled the compact Minicat model and planned to set up production in partnership with Tata Motors.
The MDI concept utilized high-pressure compressed-air tanks. The idea was that these tanks would drive pistons that, in turn, would rotate the crankshaft. However, the project never reached mass production: the system proved to be complex, expensive, and did not provide sufficient range.
The main feature of such solutions is that compressed air is not an independent source of energy. It must be generated in advance using a compressor that consumes electricity or another external energy source. Therefore, the efficiency of the entire system depends not only on the vehicle but also on the method of producing and storing compressed air.
The Rosmar H prototype demonstrates one of the unconventional approaches to vehicle propulsion, but it remains a research project for now. For practical application, it will be necessary to confirm the safety, reliability, efficiency, and feasibility of integrating such a system into mass production.
