2009 Volkswagen Jetta TDi Test Drive Clean Diesel’s 50 MPG Meets Prius-Humbling Thrust

The new era of clean diesel in America will officially be ushered in by the new VW Jetta TDi when it goes on sale in a few months. Powered by a 2.0-liter four-banger that produces 140 hp and 236 lb.-ft. of torque, it will be the first automobile to meet the world’s most stringent emission control standards, California’s Tier II, Bin 5.

Although it won’t be wearing the “BlueTec” badge, the Jetta will be using emission-cleansing technologies developed under the cooperative formed by Audi, Mercedes-Benz and Volkswagen to make it 50-state legal. Most BlueTec vehicles control NOx emissions—one of the biggest environmental hurdles facing diesels, along with particulate matter—by injecting a urea-based solution into the exhaust system upstream from the catalytic converter, where NOx is then converted into nitrogen and water. The Jetta will instead use a NOx-storage catalyst, which is basically a reservoir that temporarily holds the noxious emissions, like a particulate filter, until they can be burned off during one of the engine cycles.

In addition, the new engine will feature a common-rail fuel injection system, instead of VW’s traditional mechanical system, that uses piezoelectric fuel injectors. This technology permits higher injection pressures, which better atomize the fuel and make it easier to control pollution.

We recently test drove the Jetta through the streets of San Francisco and were pleasantly surprised. The Jetta has always been agile and zippy, but the new, more powerful TDi gives it more oomph, allowing us to power through traffic and accelerate from stoplights with authority and a little bravado—we totally tooled on a Toyota Prius. We were also shocked as to how quiet the engine operates: You have to consciously listen for the knocking, or you wouldn’t even notice it.

If reports are correct, the Jetta should get upwards of 50 mpg, combined highway and city. Although pricing hasn’t been announced, expect it to be within a few thousand of the current models (an estimated $18,000 to $23,000). We can’t wait for chance to spend some more time with the new TDi Jetta—and test its real-world feul economy. —Chuck Tannert.

© Source: popularmechanics