Taking a wide-reaching portfolio approach to reducing fuel use and emissions, BMW is using any technology that yields greater efficiencies—as long as it doesn’t undermine the performance of “the ultimate driving machine.” There’s a reason for buying a BMW, right? What’s in the portfolio? Stop-start systems (also known as micro-hybrids), regenerative braking, low resistance tires, optimized drivetrains, lightweight construction, electric power steering, and even gear shift indicators informing the driver when to upshift or downshift for maximum efficiency. BMW calls these systems “efficient dynamics”—a code word for making large fast engines a little more conservative. The company is mostly avoiding the term “hybrid,” which is perhaps too wimpy for its brand image. BMW also rolled out two pricey clean diesel vehicles in late 2008, and continues to experiment with limited-run hydrogen-powered cars. See our list of BMW models and read the latest news about the company’s fuel efficient models.