Volkswagen's TDI Diesel Hits a Snag

Looks like the much anticipated Volkswagen Jetta TDI will have its U.S. launch postponed for six months--pushed back to early summer 2008. A bugaboo with the vehicle's diesel emissions control system short-circuited its approval. Why six months? Technical changes made by engineers to fix the problem mean that the vehicle will have to go through the arduous certification process all over again.

Volkswagen completely redesigned the fuel injection system and engine to comply with strict U.S. clean diesel emissions, even skipping the entire 2007 model year to make sure the program was up-to-speed. Loyal Vee Dub diesel buyers have been patient , but there is a lot of pent-up demand for this next next generation of TDIs, and dealers are feeling the heat. According to Automotive News, Volkswagen spokesman Keith Price said of VW dealers: "They're disappointed, but they see the point that this car has to be perfect."

So what's the big deal? What is it with diesel emissions? Why is it so difficult for manufacturers to certify their diesels for U.S. sales? So very glad you asked.

• What Emissions are in Diesel Exhaust?
  
  
• How Are Diesel Emissions Regulated?
  
  
• Why is Meeting Clean Diesel Regulations so Difficult?
  
  
• What is Ultra Low Sulfur Diesel (ULSD)?