You might think that the growth spurt in the compact segment would negatively impact the fuel efficiency of these vehicles, but Edmunds' analysis shows the exact opposite. Modern-day technology has allowed automakers to build heaving vehicles that are, on average, 2.7 percent more fuel efficient than their slimmer counterparts that rolled off the lines ten years ago. If you glance at a modern compact – say the 42 miles-per-gallon rated, 3,009-pound 2011 Chevrolet Cruze Eco – it becomes obvious that a weighty ride, packed with fuel-saving technology, can also be an efficient runner.Over the years, consumer demand has increased for small cars that have more features and are more versatile in carrying passengers and cargo. Those consumer-driven desires along with the regulatory drive for enhanced safety equipment have led to size and weight increases.
[Source: Green Car Advisor]