It's been on sale in Europe for months, and now it's coming to the U.S.: the smallest engine sold by a U.S. automaker in decades.

The 2014 Ford Fiesta that goes on sale next year will offer the turbocharged 1.0-liter three-cylinder EcoBoost engine as an option in the subcompact hatchback and sedan.

Ford made the announcement today, and will officially unveil the car at the Los Angeles Auto Show, which opens to the press in nine days.

A prime example of a smaller, more powerful engine, the engine block of the 1.0-liter triple is tiny enough to fit into an airplane carry-on bag.

While it will be fitted to the Fiesta subcompact for the U.S., in Europe it's the smallest of several engine options for the Focus compact hatchback, now comprising almost 30 percent of sales.

We've even driven it, both in that Focus hatchback and also in a Focus Wagon, in its European format.

Ford projected that the 1.0-liter engine will have a rated output 123 horsepower, along with 148 lb-ft of peak torque at just 1,400 rpm.

That's more like the output of a diesel, and it's more torque per liter than any other gasoline engine sold in North America.

Ford didn't quote projected gas-mileage ratings, but it did say the 1.0-liter EcoBoost in the 2014 Fiesta would get the highest gas mileage rating "of any non-hybrid sold" in the U.S. market.

That means it would have to achieve better than the current champion, which is the 33 mpg combined rating achieved by various models of the Ford Fiesta and the Ford Focus SFE as well.

On European test cycles, the 1.0-liter returns the equivalent of 47 mpg--so a combined rating of around 40 mpg on the EPA combined cycle would be reasonable.

The 2012 Fiesta achieves EPA ratings of 28 mpg city, 38 mpg highway when fitted with a five-speed manual gearbox. Specifying the six-speed PowerShift automatic manual boosts the numbers to 29 mpg city, 39 mpg highway. Both versions are rated at 33 mpg combined.

The most fuel-efficient Fiesta this year is the version with the optional $95 SFE package that adds aerodynamic improvements and low-rolling-resistance tires, which raises the ratings to 29 mpg city, 40 mpg highway. It too is at 33 mpg combined.

Ford's 1.0-liter EcoBoost engine. Image: Ford Motor Company

Ford's 1.0-liter EcoBoost engine. Image: Ford Motor Company

Ford's goal for the engine is to match the power and drivability of a standard 1.6-liter four, which is the base engine for the current Fiesta.

In particular, it highlighted the engine's smoothness and refinement, noting in an aside that a three-cylinder from "another German manufacturer" didn't have a very good reputation for either.

That would be a dig at the 1.0-liter, 70-hp unit in the 2013 Smart ForTwo, the only three-cylinder sold in a U.S. car this year.

To compensate for the engine's uneven vibrations, Ford "unbalanced" the flywheel and other components to offset the unequal pulses.

The little three-cylinder has three-cylinder engine has been discussed as a potential race-car engine, and lapped the Nürburgring to show off its performance.

For the record, three-cylinder engines have also been sold in the U.S. over the past couple of decades in the Chevrolet Sprint, Daihatsu Charade, Geo Metro, Subaru Justy, and Suzuki Swift.

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