2010 Buick LaCrosse

Sure, hybrids and electric cars are great, but they sell in small numbers. The way most cars will meet newer, more aggressive fuel-economy rules is by making engines smaller and more efficient. Case in point: the 2010 Buick LaCrosse, a midsize sedan now offered with a 2.4-liter direct-injected four-cylinder engine generating 182 horsepower, mated to a six-speed automatic transmission. While that's far from the stunning 274 horsepower Hyundai manages to generate from the 2.0-liter turbocharged four in its 2011 Hyundai Sonata 2.0T, it motivates the midsize Buick fine in most cases. It also...