I think Dr. Marcus Parche is pretty enthusiastic about his job. He's one of the experts in passenger car diesel systems at the German electronics giant Robert Bosch GmbH. Amidst a kaleidoscope of charts and graphs in Reston, Va., last month, he regaled his autowriter audience with the benefits of cutting-edge "pumpe düse," or unit injector, diesel engine technology.
"Ze injector produces a pressure of 29,000 pounds per square inch," he explained; "and ze injection timing event is precise to between one- and two-millionths of a second. Zese tolerances are consistent at a rate of 10,000 cycles per minute."
Parche was clearly in awe of the micro-engineering that he and his Bosch colleagues have wrought. Even a layman has to admit that accomplishing the same microsecond accuracy 10,000 times a minute represents pretty dextrous handiwork with a stopwatch. It needs to be. Volkswagen is depending on Bosch's unit-injector technology to help revolutionize the way Americans think about personal transportation. This month, VW is debuting two new turbo direct-inject (TDI) diesel-powered vehicles in the U.S.: a 2.0-liter Passat TDI (in both sedan and wagon variants) and a 5.0-liter twin-turbo V10 Touareg TDI sport/utility vehicle.
Both vehicles exploit the well-timed wizardry of pumpe düse injection to deliver an impressive combination of power, fuel economy and cleaner emissions. But it's altogether another sort of timing that augurs well for VW's new diesels. With gasoline costing more than $2 per gallon, the decision to import two fuel-conscious VW's smacks of marketing opportunism of the most enlightened kind. The Passat TDI achieves 27 mpg/city and 38 mpg/highway, while the V10 Touareg TDI rates 17 mpg/city, 23 mpg/highway. Volkswagen, in other words, hopes that current events will help teach U.S. car buyers what their European and Canadian counterparts already know: Diesel is a viable alternative fuel whose technology is sophisticated, economical andbest of allalready available.
If the V10 Toureg is but a limited-production plaything for the rich and spendthrift (310 horsepower, 553 ft.-lbs. of torque, $57,800 base price and just 500 available), the new Passat TDI sedan ($23,060) and wagon ($24,060) represent Volkswagen's far more realistic effort to change the hearts and minds of U.S. autobuyers.
"In Europe and Canada," said VW's North America boss Len Hunt, "over 40 percent of all new passenger vehicles are diesels48 percent so far in '04, in fact. They're clean, quiet and economical." In a U.S. popular culture fascinated with gadgets, it's ironic how much attention is focused on novelties like "just invented yesterday" gas-electric hybrids and "just around the corner" fuel cells. Meanwhile, diesel technologists cite a legacy of 70 years' continuous development, which is all but ignored by consumers who consider themselves aficionados of the cutting edge. "Clearly we need to do some myth-busting over here in the States," said Hunt.
Volkswagen's entry-level Jetta sedan, of course, has been available for years with a 1.9-liter TDI diesel, and for 2004 Mercedes-Benz has decided to experiment with a 3.2-liter diesel (using alternative "common-rail injection" technology) in its high-end E-Class sedan. The Passat TDI, however, is targeted at the heart of the U.S. car-buying public, between college kids and high rollers. Both sedan and wagon are capacious five-seaters costing under $25-grand. They handle well. They're handsome. They manage 623 milesthat's Nashville to St. Louis and backon a single tank of fuel.
VW charges only $205 more for a Passat TDI compared with the base-model Passat 1.8 turbo. Honda's innovative Civic Hybrid, by comparison, costs over $5,000 more than a comparable base-model Civic. So long as gasoline hovers around $2 per gallon, the Passat TDI will have earned back its extra cost in as few as 20 fill-ups at the diesel pumpcompared with 289 fill-ups before the Civic Hybrid earns back its price premium.
For folks accustomed to the horsepower wars played out in American automobile advertising, the Passat TDI's output of 134 hp is going to sound anemic. But torque, not horsepower, is what translates into acceleration performance for most people. And torque it what diesels have in abundance247 ft.-lbs. worth in the Passat TDI's case. That's about 50 percent more than its typical gasoline counterparts.
So driving the TDI in start-and-stop traffic and passing folks on the freeway is virtually indistinguishable from driving a comparable gas-fueled mid-size sedan. If anything, all that torque feels even more spirited when pulling away from a stop. There's certainly no aural clue that you're driving a diesel. The TDI is eerily quiet. The five-speed automatic transmission, too, is silky smooth through the gear changes. It's torque, moreover, that gives the TDI power enough to stay in a single higher gear even under heavy loadsthere's very little of the "kick-down" effect into lower gears that's so typical of gasoline-powered vehicles when hill-climbing or making freeway passes.
Over miles through the Virginia horse country around Middleburg, driving both Passat TDIs was a grand-touring pleasure. Handling is sporty tight; the brakes are excellent; the cockpit is comfy and logically arranged. Only one tendency of the Passat TDI reminded both driver and passenger that this car was different. When backing off the accelerator just a bit after climbing a hill, the powertrain tended to "burp" with a slight shudderas if it were misfiring (although it was not a misfire, of course). There was no ready explanation for this, and it wasn't particularly annoying. Just unusual. Something to interrupt one's reverie of the moment, a reverie in contemplation of the surprising sophistication of modern diesel technologyand of Volkswagen's ambitious gamble in re-introducing it to U.S. drivers.