Re: 100:1 Mix
One more Opti-2 option for people who can't find it. Yesterday I was in my local Family Farm store (similar to a Tractor Supply) and they have opti-2 but also another product called US2 oil. Sold in the same 1.8oz packets, same mix of 1 packet to a gallon, and same fine print that it is made by Interlube, makers of Opti2.
Their site (us2oil.com) shows all the same marketing stuff as opti including the "3rd generation oil".