Over in Europe, Smart offers the ForTwo with automatic start-stop systems and in a diesel configuration that is the most efficient internal combustion car currently available. The Smart ForTwo CDi ...

“Diesel” and “sports ... This greatly improved the car’s aerodynamics (the Eco Speedster had a drag coefficient of just 0.20). The bodywork was made of carbon fiber, and gullwing doors ...

Carbon Motors has said its diesel-powered cars may cut law-enforcement fuel use and greenhouse-gas emissions by as much as 40 percent, and that building such cars may create as many as 10,000 jobs.