How is it different from the previous generations of TDI Jettas?
Volkswagen’s 2009 Jetta TDI will run on new ultra-low sulfur diesel fuel, which is available nationwide in the U.S., and is an important factor as to why the new Jetta TDI is considered “clean.” Diesel fuel used to contain higher amounts of sulfur, which were harmful to emission-reduction devices like catalytic converters that are placed in the exhaust stream to clean up harmful emissions.
With ultra-low sulfur diesel, sulfur content was reduced by 97 percent. This allows automakers to add emission-reduction devices without the risk of damaging those components. These devices will, of course, vary from automaker to automaker.
The 2009 Jetta TDI has four new devices. Volkswagen says these include an oxidation catalyst for hydrocarbon and carbon monoxide emissions, particulate emissions trap, storage catalyst for oxides of nitrogen emissions and a slip catalyst for hydrogen sulfide emissions.
Changes under the 2009 Jetta TDI’s hood include common rail fuel injection, four valves per cylinder (instead of two) and new engine calibration.
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