You can only make so much power with a certain amount of gasoline - whether it&#x27;s by a larger displacement engine, higher RPM, or using turbochargers to fill the cylinders with air.<p>If you make 300hp, it&#x27;s going to take around the same amount of gasoline to do  so whether you do it with a 5 liter V8 or a 2 liter turbocharged 4 cylinder.<p>Sure, the smaller engine is going to get better gas mileage when idling and such, and it&#x27;s amazing how efficient the larger engines are these days. But in a heavy vehicle with the aerodynamics of a brick, the EcoBoost engines aren&#x27;t seeing much better gas mileage numbers than the GM V8&#x27;s.