Automobile Magazine has named Direct Injection as a “2009 Technology of the Year”. I would certainly agree on it for 2008; may be a bit early for 2009.
Direct Injection is used on the 3.6L DI V6 and the RWD Northstar 4.6L V8 in Cadillacs. Normal fuel injection sprays fuel into the intake tract of the engine. The incoming air then mixes with the fuel to form a fuel/air vapor that travels into the cylinder. Direct Injection on the other hand uses high pressure fuel injectors to spray fuel directly into the cylinder itself. This allows the system to more closely control the combustion process, resulting in more horsepower and a slightly lower specific consumption, meaning greater economy.