They are brand new technology and only have been on the market less than a year. For the 40HP maybe less time. Seems like other manufacturers are concentrating on 4 strokes, and Evinrude is betting it all on this new 2 stroke. Me, I'd be going with a 4 stroke, I've got 2 now and would never go back to a 2 stroke. The oil for those E-Tecs ain't cheap either!