High Quality Content by WIKIPEDIA articles! TDI or Turbocharged Direct Injection is a design of turbodiesel engines, which feature turbocharging and cylinder-direct fuel injection, developed and produced by the Volkswagen Group. These TDI engines are widely used in all mainstream Volkswagen Group marques of passenger cars and light commercial vehicles produced by the company (particularly those sold in Europe). They are also used in marine engines - Volkswagen Marine, and Volkswagen Industrial Motor applications.