The Volkswagen TDI diesel engine was introduced by VAG in 1989 and was instantly recognized as an economical, yet powerful diesel engine for a mid-sized passenger car. The design featured a Turbocharger and Direct Injection fuel system by Bosch. The advanced turbocharger system increases airflow, and an intercooler lowers the intake air temperatures of the compressed air from the turbo, allowing for greater engine fuel efficiency, more power and torque and lower emissions.
In 2009, a Volkswagen Passat set a fuel economy record by averaging 67.9 miles per gallon in a tour of the 48 contiguous states. More recently, a 2012 Volkswagen Passat TDI SE was driven 1,626.1 miles from Houston, TX to Sterling, Va., breaking the Guinness record for the longest drive in a passenger car on a single tank of diesel fuel. The TDI 1.9L is no slouch either. TDI owners regularly achieve up to 220+ hp to the wheels while still averaging 50 mpg's on the highway.