The real problem is agenda interference:
Supercharger gas mileage is superior to vehicles running non-supercharged engines. This happens because an engine supercharger increases the amount of oxygen entering the engine’s combustion chamber. The greater the amount of oxygen, the more complete the fuel burns. More complete fuel burning yields greater engine power and lower emissions. Since adding superchargers to stock vehicles is not a difficult task, and because they are not very expensive, installing a supercharger is a good way to increase fuel efficiency, and gas mileage.