Rosmar teaches an Audi A8 to walk — and calls it a hypercar

## The Audi does not drive so much as haul itself forwards

Rosmar says the V-04 uses compressed air stored in 360-bar cylinders. Its rear wheels move longitudinally on guide rails rather than simply rotating in fixed positions.

The underlying patent describes a two-stage sequence. The chassis is held while at least one wheel moves from one end of its travel to the other. That wheel is then immobilised and the chassis moves relative to it. Repeating the cycle inches the vehicle forwards.

The result resembles a caterpillar track, a rowing boat or a particularly clumsy robot dog. The car moves, but the pace shown in the video is unlikely to send any EV engineering team into a panic.

Rosmar lists the prototype as 85% complete. Its own roadmap placed road testing and a new acceleration record in 2025, yet the company now says live testing is still under way and that it is seeking further funding. Timekeeping is not yet one of the project’s proven performance metrics.

## A sensible idea is trapped beneath the marketing

Romanian patent no. 132244 was not conceived as a hypercar powertrain. Its far more prosaic purpose was to help a vehicle move after becoming stuck on mud, snow, ice or sand.

If a wheel cannot gain traction, the system can reposition it relative to the chassis, immobilise it and then move the vehicle towards it. That principle could genuinely interest manufacturers of rescue vehicles, forestry machinery and other specialist equipment.

In that role, the project begins to look like a credible piece of engineering. As a replacement for a conventional road-car powertrain, it rapidly becomes a demonstration accompanied by more promises than measurements.

## 0–100 km/h in 0.3 seconds would require 9.4 g

Rosmar claims 0–100 km/h in 0.3 seconds and 0–200 km/h in less than one second. The first figure implies an average acceleration of approximately 9.44 g.

Under the simplest constant-acceleration model, and ignoring all losses, every 1,000 kg of vehicle mass would require at least:

- 92.6 kN of tractive force

- 1.29 MW of average mechanical power

- approximately 2.57 MW of mechanical power at 100 km/h

Rosmar has not published the prototype’s mass. Whatever the final figure may be, the required force and power increase in direct proportion to it, before losses in the pneumatic system, guide rails, valves and tyres are taken into account.

Traction presents an even larger problem. Without additional normal force or some form of mechanical anchoring, an acceleration of 9.44 g would require an effective tyre-to-road friction coefficient of roughly 9.44 — far beyond ordinary road-tyre performance.

Rosmar proposes what it calls “Vacuumatic Wheels” as the solution, but its public material does not provide measured suction force, energy consumption or test results on wet or uneven surfaces.

For now, then, 0.3 seconds is not a record. It is a number on a website.

## Compressed air is no free miracle fuel

Compressed air stores energy; it does not create it. A compressor must first raise the air pressure to 36 MPa, consuming energy in the process. Compression produces heat, expansion cools the system, and storage, valves and pressure conversion all introduce losses.

Rosmar’s public material does not specify the tank capacity, refill time, system mass, driving range or energy required for a refill. Without those figures, the system cannot be compared fairly with a battery-electric car, a hybrid or an internal-combustion vehicle.

The video demonstrates that compressed air can make the Audi crawl forwards. It does not show how far, how quickly or at what energy cost.

## It is a long way from European roads

The current prototype’s guide rails, pneumatic cylinders and moving wheel modules sit largely outside the original body structure. That attracts attention on a test site, but in normal traffic the exposed hardware would present obvious risks to pedestrians and other road users.

A production vehicle would require a substantial redesign of the underbody, enclosed wheel modules, crash-qualified high-pressure vessels and a control system capable of coordinating the pneumatic actuators with the steering, brakes and stability control.

Cornering creates a further engineering challenge. Any difference between the forces applied by the left- and right-hand wheel modules would generate a yaw moment, so precise closed-loop control would be essential to keep the vehicle on its intended path.

The Audi A8 conversion proves that the movement principle can propel a vehicle. It does not prove the existence of a road-ready car.

## A useful tool may emerge instead of a hypercar

The real value of Rosmar’s technology is unlikely to lie in an acceleration record. Far more interesting is its ability to reposition a wheel relative to the chassis and use it as a temporary anchor to move a stranded vehicle.

That could be useful in slow-moving rescue, off-road or specialist machinery, where extracting a stuck vehicle matters more than top speed or energy efficiency.

Rosmar can continue talking about a 0.3-second hypercar, but developing a machine that can genuinely walk itself out of the mud would make considerably more sense.

For now, the V-04 is an intriguing mechanical test bed. It can walk; only its maker says it can run.