'15 Hyundai Sonata Eco 1.6L Turbo

We’ve fired up the machinery for the 2015 Ward’s 10 Best Engines competition, now in its 21st year, and Hyundai’s improved 1.6L turbocharged “Gamma” 4-cyl. makes a compelling argument as a hybrid alternative, with a base sticker price of $23,275.

Last year, we started sharing informational spec sheets reviewed by WardsAuto editors as they judge each entry. The tally is a moving target, but we likely will end up with more than 40 new or improved engines to consider this fall. Winners will be announced in December.

The Gamma turbo, driving the midsize Sonata sedan, has come to our Michigan office and currently is under review. Here’s the sheet editors have been studying as they decide whether this 1.6L engine is deserving.

Hyundai gave us this engine to evaluate two years ago in the Veloster Turbo, and it didn’t make the cut, partly because the competition was fierce among 4-cyl. turbos.

That was the year we picked 2.0L turbos from GM, BMW and Ford. Hyundai engineers took this engine back to the woodshed to make some adjustments, and it returns with less horsepower in a bigger vehicle that is about 400 lbs. (181 kg) heavier, the new Sonata Eco, which is tuned for fuel efficiency.

On paper, given these factors, this engine should feel underpowered and sluggish. Hyundai turbocharged direct-injection engines have disappointed us for being raucous without feeling all that powerful.

But a number of editors have driven the Sonata Eco, and their reviews are favorable. To date, the car has delivered 31.2 mpg (7.5 L/100 km).

It’s balky off the line due to turbo lag/accelerator calibration, but editors say the engine is quiet, smooth and plenty powerful, even in Eco mode. Sport mode is more fun, with transmission shift points coming at higher RPM, but fuel economy is bound to suffer.

So then the question is, does this version feature enough new technology to merit a close second look compared with the Veloster Turbo reviewed two years ago?

Hyundai folks briefed us on this engine and said they redesigned the intake runners to reduce weight and improve airflow into the turbocharger. They also switched to an electric wastegate for more accurate boost control and to step up mid/high-load fuel efficiency.

The improved engine also has a higher compression ratio and a low-friction roller chain, both of which help boost fuel efficiency.

The Veloster Turbo used a 6-speed dry DCT while the new Sonata gets a 7-speed DCT with a higher torque capacity (246 lb.-ft. [334 Nm]). Hyundai says the new Sonata is the first midsize sedan using a 7-speed DCT.

Note also the horsepower peak still doesn’t arrive until 5,500 rpm after a fair amount of caning. Meanwhile, the Volkswagen 1.8L turbo-4 that won last year reaches peak hp by 4,800 rpm.

The 1.6L’s competition this year, besides VW’s excellent 1.8L turbo, will be Mini’s 1.5L 3-cyl. turbo, Alfa Romeo 4c’s 1.7L 4-cyl. turbo, Ford Fusion’s 1.6L turbo I-4 and 2.0L turbo-4s from Volvo, VW, Audi, Toyota, Subaru and Mini.

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