Abstract: An induction regulator (1) for an internal combustion engine is described wherein the regulator (1) comprises at least one perforated member (6) means for locating said perforated member (6) in the inlet manifold of an engine and further comprising adjustment means (10) to permit the angle of the perforated member (6) to be varied with respect to the inlet manifold. An induction regulator (1) apparatus is also described along with retro-fit comprising an induction regulator of the present invention as well as a method of improving the fuel efficiency of an engine using an induction regulator (1) of the present invention.