We were given two litres of Hot Stuff SuperLube 66 Racing 16% fuel to test and give feedback by our club president. He noted that the fuels were reputable and a Race blend, so we accepted the offer and proceeded to use it in an older RB just to be safe.
The engine tuned well, combustion smelled clean and the fuel performed well on track. We used exisiting older plugs and and switched happily between cold and hot with predictable tuning response. We used the two litres without cleaning the engine, used Hobbico After Run after each session and what was most impressive when we removed the head was how clean the cylinder was in the varying environmental conditions of humidty and heat over the Christmas break. The engine was run quite hard on track, it ran cool and it was remarkable as to how cleanly the fuel combusted considering we were using an older motor and a variety of plugs.
Conclusion: Runs cool, clean and can happily recommend it to anyone.