The Jetta is the first diesel vehicle to receive the award and a jury of nine environmental and automotive experts commended the Jetta TDI for its strong performance, fuel economy and low emissions.
Ron Cogan, editor and publisher of Green Car Journal commented: Hybrids have dominated the discussion of environmentally positive vehicles in recent years. The highly fuel efficient, 50 state emissions certified Jetta TDI shows that advanced clean diesel has arrived and is poised to change this dynamic. With its affordable price point, refined ride and handling, and high fuel economy, the Jetta TDI shows that hybrids now have a strong competitor in the marketplace.
The Jetta uses a 2.0 liter four cylinder common-rail TDI engine producing 140hp and 236 lb-ft of torque at 1750 rpm. Two key modifications have been made to the `Clean Diesel' engine to substantially reduce the Nitrogen Oxide (NOx) emissions. The common-rail engine in the Jetta TDI clean diesel adopts optimized combustion chamber geometry and precise injection processes at extremely high pressures to reduce the production of NOx. An exhaust gas recirculation process in the combustion chamber then reduces the concentration of oxygen with which the nitrogen can react and controls the combustion temperatures. This process can reduce temperature-dependent NOx emissions by up to 60%.
As a further measure to reduce emissions, a highly-efficient NOx storage catalytic converter soaks up any nitrogen oxides which remain. This filter is cleaned regularly, and without the driver knowing, through an automated engine management mode.
These modifications make the Jetta TDI one of the cleanest and most fuel-efficient vehicles on sale in North America. It meets the strictest emissions regulations in the world including BIN5 standard, which is equivalent to the Euro 6 standard, which becomes law in 2014.
The Jetta continues to enjoy sustained popularity in the North American market, enjoying popularity primarily with younger buyers. It is the best-selling European vehicle in the US, accounting for 40% of Volkswagen's US sales. The Jetta TDI with Clean Diesel has been available across North America since August 2008.