no, really, i do not confuse MW50 with water injection.
All those injected stuff (except GM1 called NoS by allies) are anti knocking devices.
And about the B4: no FW Anton used that fuel (except A0-A2 with C-1 engine). Technicaly impossible!
Bader's right.
The boost system introduced some time during the A-8 production run was a thing called erhoerte notleistung fur jager. It involved using extra fuel to cool the charge and prevent knocking, thus allowing the engine to run at higher manifold pressure (i.e., boost or ATA).
The Fw 190 A used C3 fuel exclusively from the introduction of the A-3, and I think the A-2 required it as well, from memory.
The Fw 190 A never used MW50, which is another anti-knocking device. The story that it used MW50 is repeated in just about every English-language history of the type, but it's not right.
Regarding what MW50 is, it is exactly the same as water injection in Allied types. It stands for Methanol Wasser at 50/50 ratio. The methanol acts as anti-freeze and also prevents corrosion. It's the water that does the work, though.
I have not seen anything to convince me that an operational Fw 190 A ever used GM1 (nitrous oxide).
Regarding why the Fw 190 A-8 in the game performs worse than the A-5, it's just wrong. In reality it got a slight increase in wing loading and a very large increase in power loading, so it should be considerably more agile, and faster than the A-5 at low altitude. Ask Oleg why he modeled it the way he did.
cheers,
Ratsack