My boss thinks 28 mpg is great. He only gets 16 mpg in his dodge 3500 van though. He complains about gas all the time and I tell him his alternatives... he just insists that gas should be no more than 1.50 / gal. Just like he yells at traffic that can't hear him.
I bet it has built in acetone injectors in the fuel tank
Actually it is probably just some re-tuning on the ECU to keep it out of V-tec longer. Regardless of what the changes are though, I want to import the parts from a new Canadian Fit to put on my year old US Fit so I can get the improvement.