Diesel particulate filter
When diesel oil is burned in an engine, soot particles are formed in the combustion chamber in certain operating areas. To eliminate these particles, Audi uses diesel particulate filters – closed-circuit systems with an efficiency of more than 95 percent.
As the particles flow into the filter, they adhere to its porous wall, and are continually oxidized as energy is supplied and converted to gaseous CO2.** The exact intervals depend on the way the vehicle is being driven. Deliberately retarding the post-injection of fuel into the engine causes the temperature of the exhaust gas to rise briefly to about 600 degrees Celsius (1,112 degrees Fahrenheit) – the cycle temperature required to burn off the particles. Audi has been installing controlled particulate filters as standard equipment on all TDI models since early 2006.
**Figures depend on the tires/wheels used.