Hello all, Well my persistent "knock" remains on my 2011 300 Race Gas Gas.... I tried 93 octane with some amsoil octane booster but it didn't seem to be any better than the 91 (with booster) that I started with. I used to run 91 with octance boost in my "regular" 2009 280. I have never heard knock before but I am pretty sure that is what I am hearing (and had a few people "in the know" listen to it to confirm my suspicion. SO..... today I bought a 5 gallon can of VP-C12, and I think what I will try first is a 50/50 mix with the aforementioned 91. I do have a few questions: What might the shelf life of the straight fuel be? I assume I can keep the unused portion for the rest of the season (10 gallons will last me quite a while). Is the metal can the best storage container? Shelf life of "mixed" oil/race fuel/pump gas? Can I store it in my plastic jerry cans? The can says "drain carburetor after each use" - will my mix be ok to leave in the float bowl between rides (usually 2 times a week, sometimes less, sometimes more)? Any other precautions that I should be aware of? Thanks!!!! as always.