Tornado is a gas-saving device that creates swirling airflow into your engine. Tornado increases your vehicle's mileage by 1-2 (MPG+) points, so you can drive an additional 30-50 miles. Every time you fill up.
Improved airflow into your engine's combustion chamber creates a more efficient mixture between oxygen and fuel creating a fractional increase in power and mileage. Over time, the fractional increase in power and mileage results in your annual savings.