The annual Ward's Auto list of "10 Best Engines" is out, but not every one of its award-winners is actually an engine.

This year, Ward's expanded its award criteria to encompass alternative powertrains, so there are two non-combustion units in what the industry trade journal justifiably calls the most diverse field of winners yet.

MORE: 2014 BMW i3: First Drive Of BMW's Radical New Electric Car

One winner is the motor that powers the BMW i3 electric car. One of four battery-electric powertrains evaluated, Ward's said it was impressed by the BMW motor's relatively broad power band. It added that the optional i3 REx gasoline range extender is a plus.

BMW i3

BMW i3

Also recognized was the hydrogen fuel-cell powertrain of the Hyundai Tucson Fuel Cell.

While it's only on sale in California in limited numbers, the Tucson still became the first fuel-cell vehicle ever to win this award.

DON'T MISS: 2015 Hyundai Tucson Fuel Cell: Hydrogen Crossover First Drive

In addition to the coup of getting a fuel-cell car to showrooms before competitors Honda and Toyota, Ward's noted the unobtrusiveness of the Tucson powertrain, praising the way Hyundai has packaged its fuel-cell stack under the hood.

It called the Tucson Fuel Cell driving experience "in a good way, completely ordinary."

2014 MINI Cooper hardtop, Northeastern road test, Aug 2014

2014 MINI Cooper hardtop, Northeastern road test, Aug 2014

Several fuel-efficient internal combustion engines were also honored, including the 1.5-liter turbocharged three-cylinder gasoline engine used in the MINI Cooper, and the 2.0-liter turbocharged four-cylinder Drive-E T5 from the Volvo S60.

New entries are pitted against winners from last year. Fuel-efficient engines making a repeat appearance included the Ford 1.0-liter turbocharged EcoBoost three-cylinder, Volkswagen 1.8-liter turbocharged four, and Chrysler's 3.0-liter EcoDiesel V-6.

SEE ALSO: 2014 MINI Cooper: Gas Mileage Review With 3-Cyl Engine + Manual

In addition to the inclusion of alternative powertrains, this year's major theme was small, turbocharged engines. Judges looked at a record 15 turbocharged fours this year, as well as the Ford and MINI three-cylinder units.

The rest of the list includes engines focused more on performance than economy: the Subaru WRX's 2.0-liter turbocharged boxer-four, the Chevrolet Corvette Stingray's 6.2-liter V-8, and the Dodge Challenger SRT Hellcat's supercharged 6.2-liter HEMI V-8.

_______________________________________________

Follow GreenCarReports on Facebook, Twitter, and Google+.