I think you'll find that most Saito users here recommend a little castor, since 1993 the bulk of my fuel has been WildCat 10 or 15% with 18% 80/20 syn/ castor blend. WildCat calls it Premium Extra. Last summer I bought 4 gallons of WildCat 2/4 fuel that is 15% nitro and 18% synthetic, so far so good.