2013 Porsche Cayenne Diesel

800-Mile-a-Tank Diesel Courtesy Porsche

Video: Get Up Close With The Cayenne Diesel

Hybrids and plug-ins are ideal for saving gas around town. For long highway trips, however, a turbocharged diesel engine may be a more efficient approach, as the Cayenne Diesel shows. Porsche engineers squeezed 240 horsepower and 406 pound-feet of torque from a 3.0-liter turbo diesel engine using electronically controlled direct injection and dual turbochargers. It’s enough to push this SUV from 0 to 60 mph in 7.2 seconds—and we still got 33 mpg on the highway and 800 miles on a tank of fuel. From $56,725