Typically, the OE stock air box and induction tube significantly restrict the airflow. S&B designs its intake kits to minimize airflow restriction, allowing the engine to breathe easier. Actual MPG results depend on a variety of factors such as environmental conditions and the presence of other modifications done to the vehicle. Typically, intakes are used in conjunction with modifications such as exhaust and/or engine tuning calibration products, to make significant increases in horsepower, and the actual results will depend on the effectiveness of those other products.
Many of our customers will naturally develop a "lead foot" because of the performance and sound increases they experience with our product. Due to this, there is no way determine each individuals driving habits.
With increased air flow into the engine, you will also need an increase in fuel to maintain a proper air/fuel ratio. This does not mean you will have worse fuel economy, you will actually have more power to move the same amount of weight as before so your engine will function more efficiently which can translate to an increase in fuel mileage. At the same time, if you were to accelerate under wide open throttle, your vehicle would be faster due to the extra power but would be using more fuel than you would at wide open throttle with the stock intake.
S&B utilizes it's 1/2 million dollar, climate controlled lab to test its intake kits and filters to the same standard (ISO 5011 Test Standard) used by the OE manufacturers, so there is substance behind S&B's test results. S&B publishes two (2) critical results: (1) Airflow and (2) Efficiency.
(1) Airflow Rating: This rating shows how much the filter and/or intake improves the airflow versus stock. By improving the airflow you will improve both the performance and fuel economy of your vehicle.
(2) Efficiency Rating: Protecting your engine while dramatically improving the airflow is S&B's competitive advantage which is why we post the efficiency numbers along with the airflow rating. The efficiency rating shows how much dirt our filters will stop. Our minimum goal for efficiency is 99.0%.