We've raved about the impressive fuel economy delivered by our Four Seasons 2012 Volkswagen Passat TDI for months now, but every so often, curious bystanders ask exactly what life with a diesel-fueled vehicle is like.
Based upon several months of use, it seems the answer is "pretty normal."
"Some Americans are loathe to drive diesel cars because they think they're slow, loud, impossible to start in the cold, and smell terrible," writes associate Web editor Jake Holmes. "That's because those people are thinking only of diesel engines from the 1980s, or of the clattery, smoking diesel school buses they rode in high school. Let's set the record straight: our Passat TDI proves that modern diesel cars are no different than gasoline-powered ones."
Sooty exhaust? A thing of the past, thanks to increasingly sophisticated diesel particulate filters. In fact, according to the EPA, the Passat TDI's tailpipe is clean in more ways than one. For every mile driven, the Passat TDI emits only 299 grams of carbon dioxide, and also earned LEVII status under the agency's BIN5 emission standards. A selective catalyst system also injects a urea solution -- known as Adblue -- upstream of a catalytic converter, allowing nitrous oxide emissions to be reduced by as much as 95 percent.
We've already heard horror stories surrounding Adblue itself. Some truckers spin tales of running out of Adblue on the road, and finding themselves unable to start the engine altogether once the tank has run dry. These aren't entirely tall tales -- if the Passat TDI runs too low on the solution, you won't be able to start (or even jump-start) the vehicle until the tank is refilled. That said, such a situation shouldn't come as a surprise -- the gauge cluster provides a warning when there's a remaining Adblue range of 1500 miles.
Frankly, we've never seen the warning. Although Adblue consumption varies depending on drive cycles and load, Volkswagen estimates the 4.9-liter tank -- which is separate from the diesel fuel tank -- provides up to 15,000 miles of travel before a refill. We're still 3000 miles away from that milestone, but another 8000 away from our next service appointment and VW says users will rarely need an AdBlue top-off between check-ups.
How about the old adage of a noisy, vastly underpowered engine? The TDI's 2.0-liter turbo-diesel I-4 quiets most of those complaints. As Holmes writes, there's a little bit of clatter during start-up, but notes our gas-powered Mazda CX-5 and BMW 328i "have similarly rattly cold-start demeanors owing to their direct injection systems and warm-up programming." As for power? "Any concerns over slow acceleration are irrelevant, given how much torque this diesel offers," says Holmes. "There is so much grunt in every gear that this 140-hp Passat TDI feels quicker in everyday driving than the 170-hp gasoline Passat I drove in fall 2011. I'd bet the average driver would have trouble noticing our Passat is a diesel purely from the way it drives." Associate Web editor Donny Nordlicht agrees: "With this turbo-diesel, I can't understand why anyone would opt for the [gasoline] V-6. The turbo-four pulls smoothly and strongly throughout the rev range and I have yet to find a time when it didn't feel like more than enough power."
The one stereotype we haven't yet been able to test? Cold weather performance. But, with winter just around the corner and Hurricane Sandy blanketing the Midwest in cold, cloudy weather, we should have our answer soon enough.