The 2015 Hyundai Sonata Eco is the most fuel-efficient version of the Korean maker's mid-size sedan, aside from its Sonata Hybrid model.

And this year, the Sonata Hybrid uses the carryover body from the last-generation model--meaning that if you want the highest-mileage Sonata with the new and more refined design, the 2015 Sonata Eco is the one.

DON'T MISS: 2015 Hyundai Sonata: Gas Mileage Review Of New Mid-Size Sedan

We've now driven the new Sonata Eco, although we didn't test it on our standard test route.

Instead, all of High Gear Media's editors took turns in the Sonata Eco during evaluation sessions for our Best Car To Buy 2015 award.

2015 Hyundai Sonata Eco, Malibu, California, Oct 2014

2015 Hyundai Sonata Eco, Malibu, California, Oct 2014

Our driving was done largely in the hills and canyons around Malibu, California, plus long stretches of traffic along the Pacific Coast Highway getting there and back from our hotel near Los Angeles International Airport.

In other words, we don't yet have conclusive data on the Sonata Eco's real-world gas mileage, since spirited driving on steep and curvy canyon roads is hardly the average use for most buyers.

MORE: 2015 Ford Fusion: Smaller EcoBoost Engine, Manual Gearbox Gone

The Eco is the sole Sonata to use a turbocharged 1.6-liter engine, in this case producing 178 horsepower and 195 lb-ft of torque. It's also the only one to use Hyundai's own seven-speed dual-clutch transmission rather than the more conventional six-speed automatic and a high final-drive ratio.

The smaller turbo four gives the Sonata lineup a further model that goes head-to-head with one in the sprawling Ford Fusion range, which for 2015 includes a new 1.5-liter EcoBoost turbo four that replaces the previous 1.6-liter version.

2015 Hyundai Sonata Eco, Malibu, California, Oct 2014

2015 Hyundai Sonata Eco, Malibu, California, Oct 2014

Hyundai offers three driving modes: Normal, Eco, and Sport. We tested the car mostly in Eco, but spent some time in Normal.

First things first: The 2015 Hyundai Sonata Eco is rated by the EPA at 32 mpg combined (28 mpg city, 38 mpg highway). The 2015 Ford Fusion 1.5 EcoBoost is rated at 29 mpg combined (25 mpg city, 37 mpg highway).

ALSO SEE: Hyundai Sonata Hybrid Carries Over, Eco Gets 32 MPG

Over 65 miles of fairly spirited driving, we averaged 27.3 mpg--but the car's trip computer logged just 18 mpg over a hilly 15-mile canyon run.

That said, we thought a few early impressions of the Sonata Eco might be worthwhile. Our notes include the following observations:

  • As 2015 Sonatas go, the Eco looks fairly stark, and its tall, low-rolling-resistance blackwall tires on 16-inch wheels underscore the plainness
  • The dual-clutch transmission exhibited no jolts or lurching at all; if anything, the software kept its shifts overly soft, sometimes leading to a hunting sensation before it selected a gear
  • In Eco mode, between turbo lag and software that keeps the engine in the highest possible gear, there's a noticeable second or two before power kicks in when the accelerator is pushed
  • Normal mode often runs the Sonata Eco one gear lower at the same road speed: noisier, but better for response
  • Sport mode also runs the engine faster and keeps it in a lower gear; you can shift manually using the shift lever in its "S" gate
  • In Eco mode, the 1.6-liter Sonata just isn't that quick off the line or in highway-speed acceleration; Normal mode is better, but it's still less powerful than any other Sonata engine
  • It's one of the two lightest model in the Sonata range at 3,250 pounds, which makes it feel more agile than versions with larger engines and more options
  • In that sense, we almost thought of it as European: a small engine that you have to work hard, in a car that's relatively light for its class

RELATED: Hyundai Sonata Plug-In Hybrid Coming Next Year, Kia Optima Too

We look forward to testing the 2015 Sonata Eco on our usual drive route to see how it compares to the version with the conventional 185-hp 2.4-liter four and six-speed automatic.

That model got 30.4 mpg on our test, against a 28-mpg combined rating.

A good omen for the Eco version? We'll see.

[EDITOR'S NOTE: An earlier version of this article cited preliminary output figures and incorrectly described the behavior of the Sport. We have corrected those errors.]


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