November 23rd, 2009 · No Comments

From Green Right Now Reports

Hyundai said that this week it will begin building a new four-cylinder engine that will be the centerpiece in its goal to becoming the auto industry’s fuel economy leader. The engine, which will be built at Hyundai’s Alabama plant, will debut in the company’s most popular car, the 2011 Sonata.

The company said its new 2.4-liter Theta II GDI engine features gasoline direct injection technology that operates with greater efficiency using less fuel, creating fewer emissions and delivering improved throttle response, all while making more power than a traditional port-injected engine. Hyundai said the 2011 Sonata will deliver 35 miles per gallon in highway driving.

Hyundai had announced in late 2008 that it would lead the industry in meeting newly proposed Corporate Average Fuel Economy (CAFE) standards, that would have required a fleet average of 35 mpg by 2020. The company said it planned to reach that target five years early through a combination of new technologies, including hybrids and gasoline direct injection. The Obama administration has since proposed more aggressive standards of 35.5 mpg by 2016, which Hyundai said it supports and plans to meet ahead of schedule.

Hyundai’s Theta I-4 engine family is a proprietary design, engineered in Namyang, Korea and currently in production for applications all over the world at volumes exceeding 2 million annually, the company said. The new Theta II 2.4L GDI engine will deliver an estimated 200 horsepower @ 6,300 rpm and 186 lb.-ft. of torque @4,250 rpm.

The most significant technology in the new engine is direct injection, which uses individual fuel injectors for each cylinder strategically positioned to deliver the optimal fuel charge directly into the combustion chamber. In a traditional multi-port system, gasoline is delivered via the port of each cylinder, where it mixes with air and is drawn into the cylinders when the intake valve opens and the piston moves down. Hyundai said a drawback to the traditional system is when engine speeds increase, the time to open the valve to deliver fuel becomes progressively shorter making accurate delivery more challenging.

GDI avoids that issue and the shorter, more direct path of fuel delivery, allows for greater control of the optimum fuel mixture at the optimum moment, thus improving efficiency. Hyundai said that compared to a conventional engine of the same displacement, GDI delivers 7 percent more torque at low engine rpm’s and 12 percent more torque at the high-end for better take-off and overtaking performance. GDI boosts gas mileage by up to 10 percent compared to a conventional engine.

Hyundai said the new GDI technology will be expanded over time to the entire family of Hyundai gasoline engines.