Gasoline Direct Injection takes the fuel injection concept about as far as it can go, injecting fuel directly into the combustion chambers, past the valves. Common in diesel engines, direct injection is starting to pop up in gasoline engine designs, called GDI for Gasoline Direct Injection. Again, fuel metering is even more precise than in the other injection schemes, and the direct injection gives engineers yet another variable to influence precisely how combustion occurs in the cylinders.
