2 Cylinder | STEYR


The M12 UI is a 2-cylinder unit injection engine with a horizontal parallel twin piston configuration. Featuring a remarkable power output in a most compact design, the M12 UI is proven and tested to work perfectly under challenging ambient conditions. The 2-cylinder unit injection engine can be combined with common DC alternators to create a diesel-electric power pack for use as auxiliary power unit (APU). By adding a permanent magnet alternator, the M12 UI becomes a very efficient genset for various applications. STEYR has introduced the STEYR E1-400 is a highly innovative electric machine that can be added to the M12 UI to create a diesel-electric generator with vast application potential. Features include:

  • Permanent magnet technology
  • Controller: active inverter
  • Nominal voltage range: 300 VDC to 400 VDC
  • Max. voltage range: 260 VDC to 430 VDC
  • Multipole high-frequency design provides low electrical ripple
  • Low maintenance and high reliability, watercooled
  • Direct engine mount for compact design


  • Chrome-Molybdenum forged crankshaft, dynamically balanced
  • Pistons are cast from high silicon aluminium with oil cooling gallery and a ceramic coated top ring
  • Hardened valve-seats high performance NIMONIC valve material
  • Elastic coupling on flywheel, design matched depending on application

Lubrication System

  • Exchangeable oil filter cartridge
  • Closed crankcase breathing system
  • Single or dual oil pump for extreme operating parameters

Fuel System

  • Integrated high pressure unit injector up to 2,000 bar with dual stage fuel injection technology, operated by overhead camshaft and rocker arms
  • Electric fuel pump (automatic bleeding capability)
  • Exchangeable fuel filter cartridge

Charging System

  • Sequential charging or single-stage intercooled charging


Vetus offers a range of 4 Cylinder diesel engines, in both Shaft and Saildrive configurations, as 33,42,52,65 and 80Hp. Engines are supplied as standard with instrument panels and four flexible engine mounts and an oil sump pump. The engines feature a water cooled aluminium top cover reducing temperature up to 15 degrees. The cooler temperature provides a more fuel efficient air supply to the engine and better combustion. Vetus manufacturers a range of auxiliary equipment for around the engine to provide a complete installation solution.


Number of cylinders2
Net weight104
Engine typeM12
Output [ps(kW)] acc. to ISO 866526.4 (36)
rom@full load3600
Fuel Consumption (G/Kwh)225
Injection systemDirect Injection
Electronic engine diagnosticNo

The STEYR MOTORS M12 2 cylinder diesel engine provides a range of opportunities in both civil and military applications for auxiliary power generation.

Its compact size and robust design using STEYR MOTORS technology makes it the perfect choice for applications requiring a portable yet quiet engine. Examples of suitable applications include mobile power generators, mobile lighting stands, forklift engine, Fire Engine Mobile Water Pressure Pump, Hydraulic pump station, mini vehicle engine, off grid power including tower and home, aircraft GPU and range extended vehicle.

In the case of off grid living, the STEYR MOTORS M12 2 cylinder can assistance within a hybrid system to deliver power or also to provide support power to air conditioning systems. It is ideal for remote locations not serviced by a conventional power grid. The STEYR MOTORS M12 is one of the few engines of this size that is controlled by an ECU as such its operation can be remotely monitored. In the event of the renewable energy source collectors becoming compromised, the small, protected, efficient diesel electric engine would be able to continue to provide power.

M12PDF3000 KBDownload