Thekmd

As a plan announced by Volkswagen, the Jetta TDI will return in the spring of 2008 as a diesel-powered vehicle and is expected to use the cleanest diesel in the U. S. The 2008 Jetta TDI will be cleared for sale in all fifty states in the country. Powered by a new 2. 0-liter four-cylinder making 140 hp and 236 lb-ft of torque, the car can use either a six-speed manual or DSG automated manual transmission. Some of the earlier introduced diesel-powered cars will only be available in 45 states. California, Maine, Massachusetts, New York, and Vermont have all adopted stricter emissions regulations for diesels that hinder the entry of some vehicles. Using advanced technology under the Blue Tec cooperative formed by Mercedes-Benz and Volkswagen, the Jetta TDI will not be affected by these stricter regulations, without resorting to a urea-based exhaust treatment, as many Blue Tec labeled models will. Nitrogen oxides (NOx), along with particulate emissions (soot), are the biggest barriers facing diesels in the U. S. The task of most Blue Tec vehicles is to control NOx by injecting a urea-based solution called Ad Blue into the exhaust system upstream of a catalytic converter that specifically targets NOx. The ammonia in the urea in that catalytic converter reacts with the NOx in the exhaust gas and neutralizes it into nitrogen and water. This catalyst is primarily a trap that temporarily holds the offensive emissions, just like the particulate filters in place on this car as well as on other diesel-powered cars. Periodically, the engine will switch to a richer air-fuel mixture. Eventually, it will create a hotter exhaust gas and burn off the material in the traps.