The spark-ignition petrol engines listed below operate on the four-stroke cycle, and unless stated otherwise, use a wet sump lubrication system, and are water-cooled. Since the Volkswagen Group is German, official internal combustion engine performance ratings are published using the International System of Units (commonly abbreviated "SI"), a modern form of the metric system of figures. Motor vehicle engines will have been tested by a Deutsches Institut für Normung (DIN) accredited testing facility, to either the original 80/1269/EEC, or the later 1999/99/EC standards. The standard initial measuring unit for establishing the rated motive power output is the kilowatt (kW); and in their official literature, the power rating may be published in either the kW, or the metric horsepower (often abbreviated "PS" for the German word Pferdestärke), or both, and may also include conversions to imperial units such as the horsepower (hp) or brake horsepower (bhp). (Conversions: one PS = 735.5 watts (W); ˜ 0.98632 hp (SAE)). In case of conflict, the metric power figure of kilowatts (kW) will be stated as the primary figure of reference. For the turning force generated by the engine, the Newton metre (Nm) will be the reference figure of torque. Furthermore, in accordance with European automotive traditions, engines shall be listed in the following ascending order of preference: Number of cylinders, Engine displacement (in litres), Engine configuration, and Rated motive power output (in kilowatts). The petrol engines which Volkswagen Group previously manufactured and installed are in the list of discontinued Volkswagen Group petrol engines article. EA111 The EA111 series of internal combustion engines was initially developed by Audi under Ludwig Kraus's leadership and introduced in 1974 in the Audi 50 and shortly after, in the original Volkswagen Polo. It is a series of water-cooled inline three- and inline four-cylinder petrol and diesel engines, in a variety of displacement sizes. This overhead camshaft engine features a crossflow cylinder head design. The camshaft is driven by a toothed belt from the crankshaft, this belt also provides the drive for coolant pump. The oil pump is directly driven by crankshaft, petrol pump and distributor are driven by camshaft. Other "V" belt-driven accessories are the alternator and (if fitted) power steering, and air-conditioning pump. In transverse mount configuration, the exhaust side is towards the vehicle firewall, in longitudinal configuration, the exhaust side is to the right as you face front in either left or right-hand drive vehicles. EA211 The