Messerschmitt Bf 109 was called the Me 109R, suggesting it was just another variant of the standard fighter, but in fact it was a racing aircraft having little in common with the Bf 109. It was powered by the DB 601ARJ, producing 1,156 kW (1,550 hp), but capable of reaching 1,715 kW (2,300 hp). This world record for a piston-engined aircraft was to stand until 1969, when Darryl Greenamyer's modified Grumman F8F Bearcat, "Conquest I", broke it with a 777 km/h (483 mph) record speed. When the Bf 109 was designed in 1934, by a team led by Willy Messerschmitt and Robert Lusser,
Messerschmitt Bf 109 variants roles, a reconnaissance or bad-weather fighter, for example. Unlike the "Rüstsatz" field-kits, these modifications were permanent. The "Rüstsatz" kits were labelled with the letter "R" and a Roman numeral. "Rüstsatz" kits did not alter the aircraft type so a Bf 109 G-6 with "Rüstsatz" II (50 kg/110 lb bombs) remained a Bf 109 G-6 and not G-6/R2, which was a reconnaissance fighter with MW 50, as suggested by most publications. The "Umrüst-Bausatz", "Umbau" or "Rüstzustand" were identified with either an "/R" or "/U" suffix and an Arabic number, e.g. Bf 109 G-10/U4. Common "Rüstsatz" kits: Bf 109G: Common "Umrüst-Bausatz" ("Umbau")