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The Mercedes-Benz 250 CDI BlueEFFICIENCY, declared the 2012 World Green Car of the Year, in on display. The Obama administration ushered in a new era of fuel efficiency standards this week by announcing new regulations aimed at doubling current standards by 2025.

New CAFE standards have been announced.

The Obama administration ushered in a new era of fuel efficiency standards this week by announcing aggressive new regulations aimed at doubling current standards by 2025.

Automotive manufacturers, who endorsed a framework for the standards a year ago, welcomed a new national standard on Wednesday while also acknowledging that the new regulations will be difficult and costly to achieve.