San Diego-based Achates Power, a firm developing clean diesel engine technology, has raised $12.1M in a $20M funding round, according to a regulatory filing by the firm today. Details on the funding haven't been released, however, the firm's backers include Sequoia Capital, Madrone Capital Partners, Rockport Capital Partners, and InterWest Partners. Achates describes its engine technology as providing both better fuel efficiency and power density than comparably sized engines. More information »