http://www.marvelmysteryoil.co...rums/viewthread/389/
http://www.marvelmysteryoil.co...rums/viewthread/272/
http://www.marvelmysteryoil.co...rums/viewthread/373/
Some light reading

The gas I use is E10. (haven't tried Valero yet, but it is cheaper than Shell, and IIRC, about the same as BP.)
IMO, I think TC-W3 works better in the gas, but MMO is good. Plus you can use it in the crankcase.