Audi debuted the 3.0 TDI clean diesel engine in the Audi Q7 SUV; now, the world's cleanest diesel technology will also be available in the best-selling Audi A4. A package of technologies provides innovative solutions for engines and the after-treatment of exhaust gas.
The engine features a new common-rail injection system (which generates up to 2,000 bars of pressure), innovative pressure sensors in the combustion chamber, and an especially high-performance exhaust recirculating system. Collectively these measures ensure a highly efficient and low-emission combustion process. A novel DeNOX catalytic converter, integrated within the end of the exhaust system, reduces residual nitrogen oxides. Just upstream of it, a pump injects an additive named AdBlue into the hot exhaust flow; there, this aqueous solution decomposes into ammonia - which splits the nitrogen oxides into nitrogen and water.
The Audi A4 3.0 TDI clean diesel quattro already complies with the emission limits of the EU's Euro 6 standard, expected to become law in 2014. It is also very fuel-efficient, with the potential to cover up to 42.1mpg (Avant: 41.5mpg). And this TDI engine is indeed a powerful performer, needing only 6.2 seconds (Avant: 6.3 seconds) to go from zero to 62mph. Top speed is electronically governed to 155mph. In conjunction with a six-speed tiptronic and quattro permanent all-wheel drive, this vehicle guarantees a high degree of comfort and superior traction.Published 6 March 2009