From the above referenced test report:

"So how did our duct tape perform?

"The KIRO fuel-saving device actually finished in first place … with a six percent increase in fuel economy!" said Beyer"

I therorize that the "Stickie" part of the duct tape was absorbed (or is the adsorbed) through the walls of the fuel line thereby inducing a drag on the fuel flow which allowed the molicues to align themselves into tighter clusters that would propogate a better flame front in the combustion chamber, which as we all know would achieve better gas milage.

 

Oh Dick, everyone knows about the old duck tape trick. Ever smell the adhesive on that stuff? Sure smells like you could run an engine on it. The adhesive diffuses through the steel fuel line and just adds more petroleum to the fuel flow.