I remember seeing ads of hand held equipment that was a mix of a 2 cycle and a four cycle....you know the ones that actually are four stroke, but still use mixed gas/oil for fuel. I believe stihl is one of the brands that have it. I believe it is called "C4 Technology"? The Shindaiwa t-2500 uses this, I just found out Anyway, how good do these things work? Are they practical, functional, etc.? What are the advantages and disadvantages of such an engine....let's talk about it a little! And how do these things work?