Hyundai 2.4-liter Theta II GDI
Direct injection, once the domain of luxury and high-performance models only, will soon be available on a humble Hyundai. The South Korean automaker has unveiled its new 2.4-liter Theta II GDI (gasoline direct injection) that will debut in the 2011 Sonata early next year.
With a compression ratio of 11.3:1, the 2.4-liter Theta II GDI delivers a peak output of 198 horsepower and 185 pound-feet of torque--enough to justify Hyundai’s decision to drop the V-6 option on the new Sonata.
Direct injection technology works by spraying fuel directly into the combustion chamber at pressures of more than 2,000 psi. This results in a more efficient burn of the fuel but it can sometimes leave a harsh ticking sound on initial cold-starts.
Direct injection benefits include improved performance and better gas mileage. Compared to a conventional engine of the same displacement, direct injection delivers 7% more torque at low revolutions and 12% more torque at the high-end for better take-off and overtaking performance. And perhaps best of all, a vehicle equipped with a direct injection engine will get about 10% better mileage than a vehicle equipped with a conventional multi-point fuel injected engine.
Over $147 million dollars and 46 months have gone into the development of the new Theta II four-cylinder, and Hyundai according has high hopes for its success. Expect to see it applied everywhere that it makes sense, perhaps built to specifications that allow for less expensive internal parts or high-performance versions, including turbo units, as well.