(July 25, 2011) DETROIT (PRNewswire) — Four is the new six. Four cylinders have replaced sixes as America's most popular engine choice, powering 43 percent of U.S. light vehicles sold in the first half of this year, according to IHS Automotive.

In 2005, V-6s were in an identical 43 percent of vehicles sold. But over six years, four-cylinder engines rose while six-bangers fell, with fours overtaking sixes in 2009. That American icon, the V-8, has lost favor even faster. It now is under one of every six hoods vs. almost one of three in 2005.

The reduction in cylinders is even starker if you exclude fleet sales, which include batches of contractor pickups and vans for rug-cleaning franchisees. So far this year, more than half the vehicles sold to retail consumers had four cylinders, up sharply from a third in 2006, says J.D. Power and Associates.

Two factors are driving the shift. Buyers beset by high fuel prices are downsizing vehicles or opting for the smaller of two engine choices. And manufacturers are shrinking vehicles and engines to meet tougher 2016 federal fuel economy rules.

Source: Automotive News