The small engines historically haven't been popular in the U.S., but automakers say the new ones pack a more potent punch.
Imagine a car that gets more than 40 miles per gallon in everyday traffic and 50 on the highway -- and it isn't an expensive hybrid, and it doesn't require special fuel.
Get ready for a new generation of cars equipped with surprisingly powerful three-cylinder engines that, according to early reviews out of Europe, have both the zip and zoom Americans expect in the four-cylinder compact sedans they buy today.
"This engine is a game-changer," Steve Cropley of Autocar magazine, a British publication, said of the three-cylinder Ford Focus that just went on sale in Europe. "You barely hear the thing start, and it idles so smoothly you'd swear it had stalled."
Better yet for power enthusiasts, "this lean upstart makes some bigger engines look puny," wrote Phil McNamara of Car, another British magazine.
Automakers are starting to test the waters for how such vehicles will sell in the U.S. market. Ford Motor Co. said it will have a three-cylinder Focus or Fiesta for sale here by the middle of next year. Mitsubishi plans to launch a compact car with a three-cylinder engine sometime in 2013.
BMW, known for its full-throttle, throaty engines, is developing a three-cylinder power plant that could show up in its U.S. offerings in three to five years. Volkswagen and Nissan also are working with three-cylinder engines, but there's no word on whether or when they will hit the U.S. market.
Automakers are proceeding cautiously because previous efforts to pack tiny engines in cars for the U.S. market mostly sputtered.
In the 1990s, Suzuki sold the Swift, and General Motors Corp. sold its version of the same vehicle under the Chevrolet Metro and Geo Metro names. While the cars' fuel economy was among the best in the industry, drivers complained that they were noisy and struggled going uphill.
The Smart Fortwo, a tiny two-seater without much power, is the only three-cylinder car still being sold in the U.S., but it's not a popular model. And because it requires premium gas, its fuel economy, at least as measured by how much money is spent on gas annually, is only slightly better than that of much larger vehicles with far stronger four-cylinder engines, such as the Honda Civic and Hyundai Elantra.
To be attractive to today's drivers, any vehicles with such small engines must be sure "not to compromise performance or fuel economy," said Rebecca Lindland, an analyst with IHS Automotive.
That's why automakers are packing more power -- as measured by horsepower and torque -- into these new engines.
The car companies are encouraged by how quickly Americans have downsized from larger engines to four-cylinder power plants. Almost half, or 47 percent, of the cars sold last year had four cylinders, according to auto information company Edmunds.com. That's up from 34 percent in 2007. Many small sport utilities, and even some larger ones such as the Ford Explorer, also come in four-cylinder models.
"Three cylinders shouldn't be much of a stretch," said Dave Sullivan, manager of product analysis for automotive consulting firm AutoPacific Inc.
Downsizing engines is part of an auto industry strategy to meet federal fuel economy standards that require the combined industrywide fleet to average 34.1 mpg by the 2016 model year, and a proposed 54.5 mpg by 2025.
Because of the way the Environmental Protection Agency calculates fuel economy for the window stickers on new vehicles, any vehicle that has a fuel economy of more than 37 mpg in combined driving probably will meet the 2025 standard.
"Everything is on the table right now with the new fuel economy standards," said Monty Roberts, a BMW spokesman.
Ford's tiny gas-sipper has the footprint of a laptop computer.
The new 1.0-liter EcoBoost three-cylinder -- the smallest engine Ford has ever built -- is turbocharged and patterned on the same technology used in much bigger vehicles, including Ford's F-150 pickup truck. The engine will pack 100 to 125 horsepower, depending on the configuration. British drivers will pay about $400 extra for the engine over the base five-door Focus.
Its horsepower and torque outputs are equivalent to or better than many 1.6-liter, four-cylinder engines now on the market, said Derrick Kuzak, Ford group vice president of global product development.
Both Ford and BMW are said to be developing even more powerful three-cylinders -- engines that could pack upward of 150 ponies, making them stronger than many of the four-cylinders that come in cars today.