[3] The original 60 kW (80 hp) 912 UL engine has a capacity of 1,211 cc (73.9 cu in) and a compression ratio of 9.1:1, and is designed to work with regular automotive gasoline, with up to 10% ethanol.

The later certified 75 kW (100 hp) 912 ULS variant has a compression ratio of 11:1, and requires 91-octane ("premium") auto gas (100LL leaded avgas can be used, sparingly).

Lubrication is dry sump, and fuelling is via dual CV carburetors or fully redundant electronic fuel injection.

[5] The 912's lubrication system differs from most dry-sump designs in that oil is forced into the storage tank by crankcase pressure rather than by a separate scavenge pump.

[3] The 912 is more fuel efficient and lighter than comparable older engines, e.g., Continental O-200, but originally had a shorter time between overhaul (TBO).

The 60 kW (80 hp) versions are sufficient to power the new generation of efficient motorgliders, such as the Pipistrel Sinus and the Urban Air Lambada.

On 8 March 2012 the company displayed its 912 iS variant, a 75 kW (100 hp) version with fuel injection and an electronic engine management unit.

[10] Unusually for a manufacturer of small aero-engines, Rotax publishes extensive warnings in the owner's manual about both the certified and non-certified versions of the engine design.