Even as we approach an age of efficient and emission-free electric cars, the internal combustion engine still shows room for improvement. Hyundai just announced its 2.4 Theta II GDI (gasoline direct injection) engine, the first instance of the automaker using direct injection with a gasoline engine.
Although there were some early adopters, automakers began replacing carburetors en masse with injection technology around 1990. But most cars today still rely on port injection, the version of this technology that was originally introduced. Direct injection squirts fuel directly into the cylinder, without going through an intake manifold first.
The advantage of direct injection is a more efficient engine. For example, Hyundai claims its 2.4 Theta II GDI gets 7 to 12 percent better torque than an equivalent port injection engine, while at the same time getting 10 percent better fuel economy. These efficiencies come due to a more complete fuel burn in the cylinder. The one disadvantage is that direct injection tends to be louder than port injection, but modern sound-deadening materials keep engine noise from being intrusive in the cabin.
Hyundai will first use the 2.4-liter four-cylinder direct-injection engine in the 2011 Sonata, which goes into production next year. The engine makes 198 horsepower and 184 pound-feet of torque. The current, port-injected 2.4-liter engine in the Sonata makes only 175 horsepower and 168 pound-feet of torque.
Hyundai follows on the heels of other automakers that have adopted direct injection, including Volkswagen, Audi, GM, and Ford.