I hear you...not what I wanted to hear either. I was hoping to knock off another 1.6kg ish on my already light 23,5kg rig. I didn't question too much and thought I wouldn't chance spending the $800 odd on it until there was WAY more data available. According to Skymax, the output is the same as the original Vitto but even amongst the Vitto exhaust models there is a difference in power output and at different rev ranges. Bob27, you've explained this very well.