Voluntary regulations / Regulatory volunteerism
EPA proposals for cleaning up legacy diesel engines imply a long-term conundrum.
|Diesels provide energy efficiencies||-->||Diesels pollute more||
||-->||The process of reducing pollution decreases energy efficiency.|
Unless the net energy output over regular gasoline is positive, diesel may not confer such a strong advantage.
And this point may well prove moot, as the proposed regulations are purely voluntary.