What’s all the talk these days about direct injection? It’s a relatively new buzzword in the industry, although some automakers have been doing it for years. Instead of placing the fuel injectors in the intake manifold to put fuel into the incoming air, direct injection sprays the fuel right into the combustion chamber. Since cylinder pressure and temperatures are much higher in a combustion chamber than in an intake port (which helps atomize the fuel), special hardware is needed, such as high-pressure injectors as well as special pistons with a specific top profile. Using sophisticated electronics, it’s possible to dramatically lean out the air/fuel mixture under cruising conditions, which improves fuel efficiency. Generally, horsepower and torque are also improved over a traditional port-injection system. Share your tips with the Auto Doc at www.theoctanelounge.com using the contact form.