[kimosabi]

This was in France, Coquelle airbase in september and october 1940. XXXX wasn't freezing there then. I'll drop a direct quote from Steinhilper himself so that you speculators can focus on something else:

"From the middle of September there was a new procedure whilst our aircraft stood 'at readiness' which showed that supplies were being tightened up on the Channel front. We didn't spot it at the time, but it was probably one of the first signs that High Command was beginning to accept that the battle was over and didn't want to waste any more supplies than absolutely necessary on it.

Normally, when we were in our Stage 1 readiness, the ground crew started the aircraft up every hour to keep the engines warm. This was to keep the engine oil thin and the moving parts ready to go at full power for a scramble. The pilots sat close to the aircraft in deck-chairs, a scene identical to our counterparts, who would be sitting a few miles north across the Channel. It was decided that this constant starting and warming up of engines was a waste of precious fuel and so a technical directive came from the head of Luftwaffe Engineering. In future, as soon as the engines had been warmed up for the first time, two litres of aviation grade petrol were to be poured into the engine to mix with the lubricating oil. Any shortfall on the oil level would then be topped up to just above normal. Then the engine was briefly run again to achieve a good mixture of oil and petrol throughout the lubrication circuit."

From the book "Spitfire on my tail" by Ulrich Steinhilper & Peter Osbourne.