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 as the design was originally conceived as a short-range interceptor. The E-7 rectified this problem as it was the first Bf 109 subtype to be able to carry a drop tank, usually the standardized Luftwaffe 300 L (80 US gal) capacity unit mounted on a centre-line rack under the fuselage, which increased its range to 1,325 km (820 mi). Alternatively, a bomb could be fitted and the E-7 could be used as a "Jabo" fighter-bomber. Previous Emil subtypes were progressively retrofitted with the necessary fittings for carrying a drop tank from October 1940. Early E-7s were fitted with the 1,100