The pro logging company that I service & repair saws for, are also a Stihl main dealer, their 2015 sales paperwork list a 4 mix Weed Whacker, & a Pole Saw, but no listing for any chainsaw other than the 2 smoke jobs, they now seem to be equipped with all singing/dancing self adjust carbs, ignition etc. but you still have to have oil mixed in the fuel & the 4mix is the same, This is in SW France so it could be different in other parts of the world, but I doubt if a company like Stihl would miss an opportunity to not launch a radical step such as a 4 stroke saw, worldwide, Maybe it"s a bit like the Comet saw from Sweden some years back that was a Diesel, but you needed to be like superman to lift it + it rattled all your teeth fillings loose.Our guys keep thrashing on with the 2 smoke jobbies.