The HiPerTEC (High Performance Toroidal Engine Concept), engineered by ATS, provides an unprecedented power-to-weight ratio in an internal combustion engine. Hundreds of pounds lighter than a traditional engine of comparable power, the HiPerTEC employs combustion processes that are far more fuel-efficient. The engine achieves the ultra-high power to weight ratio with a patented torus design that incorporates double-faced pistons set at 90° intervals, reciprocating in equal but opposite directions for vibration-free operation.

Further research and development led to the demonstration of two- and four-stroke operation of the free-piston design. This unique configuration allows for a variable compression ratio, controlled by a sophisticated computer system. To achieve this flexibility the system operates independent, pneumatically actuated, intake and exhaust valves. Adapting to power-intensive needs, the HiPerTEC offers cycle switching (four- to two-stroke) while in operation, and/or multiple HiPerTEC engines can be joined in tandem. With less weight, more power, and increased fuel efficiency, the HiPerTEC engine was the first major breakthrough engineered by ATS.