Soviet aviation fuel: More bang for the buck or the ruble?

[Paul Thompson]

Originally Posted by Juha

My contribution, in fact "Altea"'s
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I recall reading years ago, that one of the USSR's main offensive in 1944 was delayed a few days/a week on Stalin's order in order to get LL 100 oct fuel for a P-39 fighter division, which Stalin thought would make an important contribution to the air part of the offensive.

Juha

Hello Juha,

Thank you for your help!

To summarise what Altea wrote, the following appears to have been the case:

1. The 2B-78 and 3B-78 gasoline grades were used for the M-105 series engines and the 4B-78 for the M-82 series. Why did the M-82 use a higher quality fuel?

It is interesting that the M-107, a development of the M-105, used 3.5B-78, yet another variation!

2. The German C3 grade had an octane rating of 94, according to Soviet TsAGI (Central Aerohydrodynamic Institute) data. It is not stated whether this was a MON or RON rating, but I suspect they used the Cooperative Fuel Research (CFR) engine to measure MON ratings. This would not conflict with the German 100 octane rating of C3, since that should be a RON rating, which is always higher than the MON figure.

Altea quotes some Soviet source as saying that the Soviet 93 octane rating corresponded to the German 96 octane, because of different measurment procedures, which would reinforce the point above.

Soviet octane ratings for mixtures of basic gasoline and 'R-9' ethyl fluid are given in Alrea's very useful table. On the basis of this table, it would appear that there was no B-89 grade, contrary to Tango Echo Dog's initial post. 4B-70 and 3B-74 seem to be the most likely candidates for an 89 octane equivalent fuel.

Having written the above, I have to say that much remains unclear. The key questions that remain are as follows:

1. What fuel grades did the Soviets use for which aircraft? Was 4B-78 or 3B-78 the most common fuel used, or did this change over the course of the war?

2. What were the MON and RON ratings of German fuel and can these be directly compared to Soviet ratings?

3. As mentioned by Juha, how much Lend-Lease gasoline did the Soviets have and when?

I hope that some forum members might have statistics from the US side, on the quantity of aviation gasoline delivered to the USSR and the octane grades of this gasoline.

Regards,

Paul