SEOUL -- With new fuel economy regulations coming during the new Sonata’s model cycle, Hyundai decided to go with a turbocharged direct-injection four-cylinder engine for the mid-sized car instead of throwing a V-6 into the engine bay.
The result is not only better fuel economy than its V-6 rivals, but also a claimed advantage in horsepower and torque.
The basics: Hyundai claims the horsepower and torque output of its four-banger turbo exceeds that of 2.0-liter turbo offerings from Volkswagen and Buick, and also the V-6s from Ford, Chevrolet, Toyota, Honda and Nissan. It’s also more powerful than the Hyundai V-6 it replaces.
Hyundai’s turbo also creates the best power-to-weight ratio in its class and delivers 22 city/34 highway fuel economy numbers with a ULEV-II emissions rating.
Notable features: Hyundai went with a twin-scroll turbocharger, which has smoother power uptake and delivery than a typical single-scroll turbo. It says the added cost was about $30 per unit. The intercooler also has an air-guiding duct for cooler and more direct airflow into the turbocharger, resulting in an extra 5 to 8 horsepower.
The turbo engine, which is teamed with a six-speed automatic transmission, has variable valve timing for both the intake and exhaust valves. Turbo models also get dual exhaust and monotube shock absorbers, upgrades from the base engine model.
What Hyundai says: “We had a very aggressive development target for the turbo,” said Moon Dae-hyung, Hyundai Motor executive vice president. “We knew that driveability and NVH [noise, vibration and harshness] could not be sacrificed compared to V-6 engines.”
Compromises and shortcomings: Hyundai claims a 6.5-second 0-to-60 time, but crude hand-timed acceleration tests by journalists were more in the mid-eight second range. Hyundai could have turbocharged the base 2.4-liter four-banger to create a real screamer, but it decided a smaller-displacement engine was a better platform to achieve fuel economy gains.
The market: The new Sonata goes on sale Sept. 1. Hyundai expects about 20 percent of Sonata shoppers to choose the turbo version, which is about the same ratio as those who pick a V-6 in the segment.
The skinny: Buyers will have to be convinced that slapping a turbo onto a four-cylinder engine carries the same premium as a V-6 option. Then again, numbers don’t lie. If Hyundai’s four-banger delivers the power and fuel economy as claimed, it’s a strong contender.