Volkswagen Jetta Clean Diesel 2008

I'm just clearing customs on my way home from Europe when my cell phone rings. It's Keith Price, our favorite Volkswagen product rep, calling. He's on his way to Ann Arbor in a 2004 Jetta, and he wants me to drive it. A 2004 Jetta? Keith is obviously up to no good, so I immediately agree to meet him.

He volunteers to rendezvous at my house, since I'm not going into the office, and I rush home. A few minutes after I get there, a blue Jetta pulls into my driveway and sits there, idling. I walk outside meet them - it's Keith and Norbert Krause, director of the Engineering and Environmental Office. They're both smiling.

A few seconds pass, and I realize they're smiling because I haven't figured out what's going on yet. I listen carefully, and I can just barely hear the faint clatter of a diesel. This particular car might be a few years old, but under the hood is something brand new: next year's 2.0-liter, sixteen-valve Clean Diesel.

The last Jetta TDI sold here was the 2006 model, which had a 1.9-liter four-cylinder with 100 hp that was rated at 30 mpg city, 38 highway. That's not bad mileage - and it was significantly better than the gas engines - but that diesel's technology is nearly ten years old.

Beginning early 2008, the Jetta will again be available with a diesel - a 2.0-liter unit that pumps out 140 horsepower and 235 lb-ft of torque - but this time, it comes with all new technology. (Incidentally, though it's the same displacement as the 2.0T FSI, the engines don't share any major components.)

The new engine's fuel injection system uses piezo injectors and operates at up to 1800 bar - that's a staggering 26,000 psi. The ultrahigh pressures help ensure that the diesel atomizes and combusts completely, maximizing power and minimizing pollution, smoke, and noise. Air is force-fed into the cylinders via a variable turbine geometry turbocharger that helps minimize turbo lag.

More importantly, the Clean Diesel is 50-state legal, meeting the ultra-strict BIN5 ULEV2 standards. It uses a selective catalytic reduction system that is maintenance-free for 120,000 miles, and no urea injection is needed. Despite the big bump in horsepower, the new engine produces a staggering 60 percent fewer emissions than the old 1.9-liter.

Source : www.automobilemag.com