Hyundai Sonata 2.0T, 2011

Hyundai Sonata 2.0T, 2011

 

Hyundai Motor America debuted its 2.0-liter Theta II turbocharged gasoline direct-injection (GDI) engine in the 2011 Hyundai Sonata 2.0T at the 2010 New York Auto Show. With the addition of the all-new 2.0-liter Theta II turbocharged GDI engine, the new 2011 Hyundai Sonata offers an unprecedented combination of segment-leading fuel efficiency and power - with an estimated 34 mpg highway rating, and 274 horsepower. Remarkably, the Hyundai Sonata 2.0T produces these industry-leading metrics on regular fuel…premium fuel is not required.

The new Hyundai Sonata is the first Hyundai vehicle to have both GDI technology and a turbocharger. By the end of Hyundai's 24/7 version 2.0 product initiative (seven new models in the next 24 months), four nameplates will be available with GDI or the combination of GDI and a turbocharger. Turbocharging and GDI are part of "Hyundai Blue Drive," the company's environmental initiative to continue industry leadership in fuel efficiency and sustainability.

The 2.0-liter turbocharged GDI four-cylinder engine in the 2011 Sonata produces 274 horsepower at 6,000 rpm and 269 lb-ft of torque from 1800-4500 rpm with regular fuel. The Hyundai Sonata 2.0T will deliver 22 mpg city and 34 mpg highway (preliminary estimates). Hyundai's turbocharged engine features a twin-scroll turbocharger that when combined with the GDI system results in instantaneous power delivery. Twin-scroll turbochargers have traditionally been used on more expensive high performance engines, but as with GDI, Hyundai has chosen once again to apply this efficient technology in high volume to its most popular model.

The 2.0T engine will be available on the SE and Limited trim level, with the 2.0T Limited getting additional upgrades, including:
  • Panoramic sunroof
  • 18-inch hyper silver alloy wheels
  • Dual exhaust system
  • Steering wheel-mounted paddle shifters
TWIN-SCROLL TURBOCHARGER AND GDI TECHNOLOGY
Twin-scroll turbocharger designs have two exhaust gas inlets divided by split walls inside the turbine housing, with both gas passages controlled by a waste-gate. A twin-scroll turbo recovers even more energy from the exhaust than a single-scroll turbocharger thanks to a divided manifold. The twin-scroll design separates the cylinders whose exhaust gas pulses interfere with each other resulting in improved pressure distribution in the exhaust ports and a more efficient delivery of exhaust gas energy to the turbocharger's turbine.

The twin-scroll turbocharger design has several other advantages over traditional, single-scroll turbocharging systems, including:
    * Improved combustion efficiency
    * Low engine-speed efficiency
    * Kinetic exhaust gas energy is not wasted or trapped
    * Cooler cylinder temperatures
    * Lower exhaust temperatures
    * Leaner air/fuel ratio
    * Better pressure distribution in the exhaust ports and more efficient delivery of exhaust gas energy to the turbocharger's turbine

Essentially, Hyundai Sonata's twin-scroll turbo directs even more air into the engine while a compressor increases the pressure entering the cylinder. This allows the air entering the cylinder to be even more densely packed for higher compression and better performance, contributing to a more-efficient burn and fuel efficiency.

Two key features of Hyundai's twin-scroll turbocharger setup are:
  • The stainless steel exhaust manifold and the twin-scroll turbine housing are cast in a patent pending one-piece design
  • The waste-gate for the turbocharger uses a motor-driven electrical controller instead of being mechanically controlled
By adapting the motor-driven electrical waste-gate, the boost pressure is precisely controlled. The back pressure is reduced when turbo boost is not necessary by opening the waste-gate, which improves fuel efficiency. In addition, during cold starts, the waste-gate remains open which results in faster catalyst light-off for reduced exhaust emissions.

WORLD-CLASS POWER-TO-WEIGHT RATIO, RIGIDITY AND SPACE
One of the program targets for the 2011 Sonata engineering team was world-class power-to-weight ratio. This philosophy was also applied to the Hyundai Sonata 2.0T, with the result of a best-in-class power-to-weight ratio of 12.2 horsepower per pound, significantly better than any mid-size sedan competitor, and even better than the performance-focused Chevrolet Camaro V6. Power-to-weight ratio pays dividends in both performance and fuel economy, and is the key to Hyundai Sonata's superior performance in both of these areas.
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