Driving more using less fuel

That works because, in most cases, the engine is operating with a lean fuel condition. Which helps fuel economy no matter how you get there. It was what allowed the Civic VX to achieve its high fuel efficiency. Lean burn has its own issues, though. First is that lean air mixtures are a great recipe for producing NOx. Next is if they are too lean, they burn hotter. Which usually ends with a hole burned through the piston head with engines not designed with lean burn in mind.

 

State governments would push hard for a gas tax increase to make up for revenue short falls.

DBCassidy