Time was when mid-size sedans routinely came with V-6 engines of 3.0 to 3.6 liters. But these days, those are rare and expensive high-end options--if they're even offered at all.

The 2015 Ford Fusion sedan now has a simplified lineup of engines, and all of them continue to have just four cylinders--but one has gotten smaller.

When the redesigned Fusion launched as a 2013 model to rapturous reviews for its sleek styling and comprehensive features and options, it came with three engine choices.

DON'T MISS: 2015 Ford Fusion - full review

One was a 175-horsepower 2.5-liter base four-cylinder, to give a lower base price and, we suspect, for fleet purchasers more concerned with sticker price than fuel economy. We've never actually been able to find a Fusion 2.5-liter to test-drive.

Ford Four-Cylinder EcoBoost Engine

Ford Four-Cylinder EcoBoost Engine

The more common engines for 2013 were two EcoBoost turbocharged fours: a 178-hp 1.6-liter and a 231-hp 2.0-liter. The 2.0 was the most powerful, and the only engine offered with the Fusion's optional all-wheel drive.

Then for 2014, a third EcoBoost four appeared: a 181-hp 1.5-liter, slightly smaller than the 1.6. If you wanted the smaller EcoBoost with a six-speed automatic, you got the new 1.5, but the previous 1.6 continued if you happened to choose the six-speed manual gearbox.

We drove that 1.6 manual Fusion a couple of years ago, and it was great fun--but U.S. buyers simply don't order manuals in mid-size sedans any more. Even Subaru has eliminated the manual option altogether from its new 2015 Legacy.

So for 2015, the lineup is simplified: the 2.5-liter base engine stays available (at least nominally), the 1.5-liter EcoBoost plus automatic is the smaller of the two engines buyers actually order, and the 2.0-liter with automatic remains the most powerful engine.

Net-net: The 1.5-liter has supplanted the 1.6-liter after a transitional year. And there are no more manual Fusions at all. [sigh]

The 1.5-liter EcoBoost gives the same 28-mpg combined fuel-economy rating as its 1.6-ilter predecessor when both are fitted with the six-speed automatic.

But for 2015, buyers can choose to add a Start-Stop system to the 1.5 that boosts that rating 1 mpg to 29 mpg, an option not offered on the Fusion 1.6.

2014 Ford Fusion 4-door Sedan SE FWD Dashboard

2014 Ford Fusion 4-door Sedan SE FWD Dashboard

The performance of the marginally smaller 1.5-liter EcoBoost is within a tenth of a second of its predecessor, though reviewers have noted that its peak power comes in at a higher engine speed.

That means the engine may have to be revved slightly more, especially in around-town driving.

ALSO SEE: 2015 Ford Focus EcoBoost Three-Cylinder: Manual Gearbox Only

The Fusion's 1.5-liter EcoBoost four is currently its smaller engine.

But Ford's smallest EcoBoost turbo--the tiny 123-hp 1.0-liter three-cylinder--is coming to the Focus compact lineup this year, though only with a six-speed manual gearbox.

We drove that engine in a 2014 Fiesta (with a five-speed manual) and enjoyed it greatly. Plus we got a genuine 40 mpg-plus on our particular test cycle of about two-thirds highway and one-third city and suburban driving.

2015 Ford Fusion Hybrid

2015 Ford Fusion Hybrid

But while the Ford Fusion is actually going to be offered with the 1.0-liter three in Europe (where it's sold as the Mondeo), there's no sign so far that a three-cylinder mid-size sedan is on the horizon.

MORE: Europe's Ford Fusion Gets 1.0 EcoBoost: How Small Is Too Small?

Which seems rather a shame--though it makes sense, given greater U.S. driver expectations for acceleration and highway passing power.

Still, we can dream.


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