2009 Volkswagen Jetta TDI: Living the low [rpm] life

摘要

JUST OVER A YEAR AGO WE TOOK DELIVERY of a conservatively equipped Jetta TDI for a long-term test. A far cry from a diesel sports car or even one of those rare diesel SUVs capable of towing a small city up a 30-percent grade, the TDI came armed with 140 bhp and raw resolve in an attempt to appease our lust for motoring entertainment. You might say it had its work cut out for it. Now, 45,000 miles later, the Jetta TDI is a car our staff can't get enough of. One of the downsides of some modern "clean" diesels being sold in the U.S. market today is the need to fill their NO_x-reducing urea supply when it runs low. Some argue this is a non-issue since the refill is usually done during a vehicle's regular scheduled maintenance. But say you're a member of that infinitesimal group who doesn't adhere to a manufacturer's recommended maintenance schedule exactly, and you run out of the stuff during a road trip? Well, these new cars are designed not to start in such cases, after a short grace period. With our Jetta's small 2.0-liter turbodiesel engine, there's no need for a urea supply. Instead, VW burns off the NO_x by periodically running a richer fuel mixture.