Its pretty straight forward, although the biggest results come from adjusting the nut behind the steering wheel. Blocking the outside of the grill openings, removing stuff so air flows smoother around the car, increasing tire psi, lowering vehicle to pass through the air better, air dams to close gap between car and road, covering under side to reduce drag. Take a look at the rear of your car to see if the rear is like a parachute for catching air. Also if you make short v slong trips you may see a increase in forgoing the cold air intake and sucking in warm air from under the hood. Ive seen mixed results depending on vehicle, but for the most part short trips vehicles improve with warm air, longer trips vehicles mpg improves with cooler air.
Me, I like to use water wetter and a full grill block in the summer.
