Yea right, changing the air filter type gives 5% increase in MPG? Anyone else here consider how this can happen when you're running the engine at low RPM's and no where NEAR the limit of the factory filter's flow rate.
My bet is he is driving differently -trying- to get better MPG so his filter will do something. Don't you think the factory would use these filters if they really did give a 5% increase in MPG as is guy claims? They know better MPG will sell more trucks and they spends hundreds if not thousands making the vehiles lighter, better areodynamics in a wind tunnel ect trying to acomplish what this guy claims he did for $35.