Luftwaffe Fuel Names

[AndreasB]

Can someone explain to me what the following fuel types are?

B4
C3

Many thanks!

All the best

Andreas

[carlmu]

B3\B4 Kraftstoff 87 oktan
C3\C4 Kraftstoff 100 oktan

Carl

[AndreasB]

Many thanks! So C3/C4 would be needed for high-performance engines e.g. in the Me 109, while B3/B4 could be used for the Ju Ju 52?

All the best

Andreas

[John Beaman]

Carl and Andreas:

I was under the impression that B4 and C3, seen later in the war were the equivalent of coal oil derived fuels, equal, respectively, to the 87 and 100 octane. This happened after "pure" petrol distilled from natural oil could not be had easily. 100 was used for higher performance engines like the DB 601N and for supplements like GM 1. Later engines, at least liquid cooled ones, could be tuned to take either when one or the other was not available.

[NoNo01]

Gentleman,

regarding Lange, Bruno ; "Typenhandbuch der deutschen Luftfahrttechnik" page 357 - 360, this where designations of the RLM-Klassifizierungssystem für Flugkraftstoffe (roughly - RLM-classificationsystem for aeronautical fuel).

Here we find the following designations:A1, A2, A3, A4, A5, B1, B2, B3, B4, C1, C2, C3, K1 and J1 with there technical data.

For example; B4: OZ(Oktanzahl - You guest it? octane number) 87; 0,71 - 0,76 kg/l, TEL (Tetra Ethyl Lead) up to 0,12 Vol%, Temperature of ebullition between 40° to 170° C (90 Vol% up to 160°C), Cold-resistant to -60°C.
Used for example with: As 410A, BMW 132A and Dc, 801A and C, DB 601A and E, Jumo 211F, 213A.

C3: OZ 96 0,76 - 0,795 kg/l, TEL up to 0,12 Vol%, Temperature of ebullition between 40° - 180°C, (90 Vol% up to 165°C), Cold-resistant to -60°C.
Used for example with: BMW 132H, 801D and G, DB 601N, 603S and 605A.

Maybe You find this interesting

Schoene Gruesze

Norbert

[Kurfürst]

You can read some of the more interesting German aviation fuel related material on my site, collected from various sources. A lot more can be found at the Fischer-Tropsch Archive site, but most of it is so technical that it may be uninteresting for most of us.

http://www.kurfurst.org/#engines, see aviation fuel section.

In short, B-4 and C-3 are designations for German synthetic fuel. B-4 is roughly 87 octane, whereas C-3 is roughly 96 octane. Take note that the Germans measured octane number by a different method than the Allies, and that to composition and performance of especially C-3 changed during the course of the war. Briefly, early was C-3 was equivalent to 96/130 Grade Allied fuel, and from late-1942, 96/145 Grade fuel.

There's little rule as for what fuel was used, it depended on the engine, and these were not seperate 'bomber' and 'fighter' fuels. B-4 was typically used by 109s (with exceptions: DB 601N powered E-something/N and F-1, F-2 versions used C-3) and bombers from early to mid war; late war 109G/K with methanol boost was typically prescribed to use C-3, but could 'fall back' to use B-4 if that was available, with little or no performance loss. BMW 801D engined Fw 190s used C-3 (very early 190s with 801C theoretically used B-4 but I believe they used the better C-3 regardless).

Almost all bombers used B-4 for their engines, but this was not set in concrete either: there's evidence that 1940 Ju 88As and late 1944 He 111H-16s used C-3, even though there would be no advantage from it; probably it was handier at the airfield than B-4, and so was used..

[AndreasB]

Many thanks, very helpful! I am wondering why it seems that consumption of stocks during CRUSADER in late 41 seems to have been primarily B4, while C3 stocks were left untouched?

Planes present in numbers in North Africa would have been Ju 88 A4, Me 109 F-4, Ju 87 R2 and R4, Bf 110A and N, Ju 52, some He 111, and various curiosities.

Any ideas?

All the best

Andreas

[Juha]

Hello
surely no Bf 110As around, probably C-E. Only type absolutely needing C3 was Bf 110C-?/N, N reveals they had DB601N engines which needed C3 fuel.

Juha

[AndreasB]

Hi Juha

Many thanks for the correction. I just went by what it says on the intercepted strength returns.

All the best

Andreas

[Kurfürst]

Indeed as Juha says, the "110A" is almost certainly planes with DB 601A (B-4) and the "110N" are planes with DB 601N (requiring C-3). I suppose if there were mixed 601A/601N units then they probably used only C-3 in all planes, to avoid nasty accidents.

I suppose Bf 109E (many if not most of the E-7 were built with 601N) and F-1 or F-2 (all DB 601N powered) would be the other C-3 users.

All the rest could do with B-4, but at the same time could use the better C-3 as well, but not vica versa; there are, for example records of Ju 88A shoot down in the BoB found with C-3 in the fuel tanks, though B-4 was perfectly sufficient - and prescribed - for it's Jumo engine.