Messerschmitt Bf.109F, German Users - part seven

The DB 601E rated at 1332hp (993Kw or 1350Ps) was fitted to the F-3 and F-4 versions together with a VDM 9-12010 propeller which featured broader blades to improve high altittude performance. Initially, the DB601E was limited to 1184hp (883Kw or 1200Ps) but that limit was removed in February 1942. It ran on standard 87 octane B-4 aviation fuel, in spite of the increased performance, while the earlier DB601N required 100 octane C-3 fuel.
It's believed that just 15 aircrafts of the F-3 variant were produced, which it's believed that they served as the pre-production for the upcoming F-4. They were manufactured by Messerschmitt Regensburg between October 1940 and January 1941. Like the F-1, it was armed with one 20mm MG-FF/M firing through the propeller hub. plus two 7.92mm MG-17.
The F-4 introduced the new Mauser 20mm MG151/20 replacing the motorkanone, and firing it through the propeller hub. The first ones rolled out from the factory in June 1941 and they were produced exactly during one year, from May 1941 until May 1942 with a total of 1841 F-4 of every sub-variant built. Some of the late sub-variants featured two MG-151/20 cannons mounted under the wings in faired gondolas. They were designated F-4/R1 and 240 were built by WNF in the first quarter of 1942. This optional armament was standarized as a kit in the later G and K variants. Another high-altittude variant, the F-4/Z featuring a GM-1 boost was also manufactured with a production run of 544 in that first quarter of 1942 and they were extensively used. Erla factory, produced the tropicalized F-4/Trop variant, in the first half of 1942.
With the initial engine rating of 1184hp the maximum speed that the F-4 could achieve was 635km/h (394mph) at a rated altittude and when the engine was cleared to work at maximum power of 1332hp, the maximum speed increased to 659km/h (410mph) at 6200m high (20341ft).
There were also some reconnaissance variants, with cameras fitted under the fuselage aft of the cockpit, built in small numbers. They were designated F-4/R2 and F-4/R3 and just 41 of them were built. Five of the R2 sub-variant and 36 of the R3.

Sources:
1. https://en.wikipedia.org/wiki/Messerschmitt_Bf_109_variants#Bf_109F
2. Salamander Books - The Complete Book of Fighters
3. Osprey - Air Vanguard 23 - Messerschmitt Bf 109 E-F series
4. Signal Squadron - Aircraft In action  57 - Messerschmitt Bf-109 in Action Pt.2