Me Bf 109 F-4
- F-4 (As F-2 but with DB 601E engine, 20 mm MG 151/20 "Motorkanone" cannon replacing the 15 mm MG 151)
- F-4/R1 (capable of mounting two 20 mm MG 151/20 cannons in underwing gondolas)
- F-4/R2 (dedicated recon version, 5 built)
- F-4/R3 (dedicated recon version, 36 built)
- F-4/Z (As F-4, high-altitude fighter with GM-1 boost)
- F-4 trop (Tropicalized fighter)
The 1,350 PS (1,332 hp, 993 kW) DB 601E was used in the F-3 and F-4 model together with a VDM 9-12010 propeller with broader blades for improved altitude performance. The DB 601E was initially restricted to 1,200 PS (1,184 hp, 883 kW) at 2,500 rpm; however, the full rating of 1,350 PS at 2,500 rpm was cleared for service use by February 1942. The DB 601E ran on standard 87 octane "B-4" aviation fuel, despite its increased performance; while the earlier DB 601N required 100 octane "C-3" fuel.
From the F-4 onward, the new 20 mm Mauser MG 151/20 with 200 rounds was used as the Motorkanone. The first F-4s reached frontline units in June 1941. Production lasted exactly a year between May 1941 and May 1942, with 1,841 of all F-4 variants produced. Some of the later models were capable of mounting two 20 mm MG 151/20 cannons under the wing in faired gondolas with 135 rpg. These were designated F-4/R1 and 240 of them were produced by WNF in the first quarter of 1942. This optional additional armament was standardized as field kit for later G and K series. A special high-altitude variant, the F-4/Z featuring GM-1 boost, was also built with a production run of 544 in the first quarter of 1942 and saw extensive use. Finally, the Erla factory produced 576 tropicalized F-4 trop in the first half of 1942.