The BG86 isn't 4-mix technology. But I do agree with the HS45 being a good machine($299.99). That's all I keep in my store because that's what all my commercial guys use. But now they are only coming with a 18" blade though:/ They came out with a HS46 C-E that comes with a 22" blade($359.99), Its is a new startified scavenging engine on it (just like the BG86). These new engines are supposed to cut down on emissions.