The Chevrolet Bolt EV is displayed during the Los Angeles Auto Show at the Los Angeles Convention Center on November 20, 2016 in Los Angeles, California.

A leading auto industry researcher has for the first time ranked four electrified powertrains among its list of the top 10 engines.

For the first time in its 24 years of existence, WardsAuto's Top Ten Engines List included one fully electric car, a hybrid, a plug-in hybrid and a hydrogen fuel cell car. That would mean four of the top 10 automotive engines for 2018 are not engines at all.

The fully electric Chevrolet Bolt, the plug-in hybrid Chrysler Pacifica, the hybrid Toyota Camry, and the hydrogen fuel cell Honda Clarity were all included in the list, which evaluates powertrains on cars priced below $50,000 that are for sale in the U.S. by the end of the first quarter in 2018.

The team did not set out to include so many electrified vehicles, WardsAuto senior content director Drew Winter told CNBC. The team focuses on engines or powertrains that add an exceptional degree of value of the car, and factor in practicality and value.

"There were a lot this year just because the industry is coming out with so many alternative powertrains that are really good," Winter said. "We are letting consumers know, you don't have to buy this because you have to or because you feel you should. It is really a part of the value proposition of the car."

Perhaps the least accessible car on the list for buyers is the Honda Clarity fuel cell car, which for now is only available in California. Hydrogen fueling infrastructure is severely limited to just a few regions of the country.

Despite that, it is a pretty strong value for customers who happen to be in an area where they are available, Winter said.

One well-known electrified powertrain missing from the list is the Tesla Model 3, which went into production in July and starts at $35,000. The team did not include the model because they could not get a car for testing. WardsAuto did not evaluate the Chevrolet Bolt in 2016 for a similar reason, Winter said.

One unusual note about this year's list is the total absence of any cars from German manufacturers, particularly the higher-end brands. Also unusual is that there were only two returning winners this year — the Chrysler Pacifica Hybrid and the Infiniti Q50. This was primarily due to sheer competition.

"Really what that tells us is that engine technology powertrain technology is really advancing fast now. There are just so many new propulsion systems.

Here is the full list of winners: