Greg recommended roughly 2TBS of Marvel Mystery Oil per jerry can (20L or ~5gal) as it is a dry fuel and needs and that was apart of the concotion for that run. Initial pull with avgas was fairly rich which is an indicator of a good race gas - plenty of room to lean it out for more power. They've done avgas tunes in the past in the early days but have not done so with their more modern equipment according to Seb. They did not have concerns with it by the end of tune. 100LL with a proper tune shouldn't foul O2 sensors any more than regular pump fuel - just gotta be cat free. Other notes... 100LL is rated with a different standard but apparently its a true 100 octane fuel. It's fairly available depending on your local airports policies and around it is comparable to pump fuel prices. Since there is no ethanol it stores better. It has a sweet smell after combustion. Overall im happy. Since i have no knock protection of any kind using 100LL made sense since the fuel quality is generally consistent throughout the world I would assume as an aviation fuel.