I have worked on one of the newer stihl 4 mix -- 4 stroke with no crankcase oil just like 2 stroke mixed I was a little happy to see it but the coil was bad we are not a stihl dealer so the customer took it to the nearest dealer before he left he said his stihl dealer was having problems with them. the 4 mix took the place of the 25.4 2 stroke on the pro weedie. in small words I"M NOT IMPRESSED. thanks for listening