Short Take Road Test
As we go to press in early 2004, VW has the diesel passenger-car market sewn up in this country-its Golf, Jetta, and New Beetle TDI models account for all 100 percent of it. Coming later this year is the Touareg V-10 TDI and a new 2.0-liter Passat TDI (plus the Mercedes E320 CDI and Jeep Liberty).
These cars are legal for sale-only in states that do not adhere to California's emissions regulations-under a Tier II phase-in scheme that is too complex to elaborate here. Suffice to say that this Jetta meets a standard that permits 0.20 to 0.30 gram of NOX per mile and limits particulates to 0.06 gpm, a standard that will ratchet down in the next few years. The NOX hurdle was cleared by adding a new intercooler to lower the temperature of the recirculated exhaust gases. This air-to-water intercooler also helps warm up the heater more quickly in the winter. New electronic unit injectors driven by the camshaft helped boost fuel-injection pressure from 27,500 to 29,700 psi to cut particulate emissions.
As so often happens, changes driven by emissions regs yield power dividends as well, and here the output climbs to 100 horsepower and 177 pound-feet, up 10 horses and 22 pound-feet. The 2.0-liter Passat will add the breathing benefits of a 16-valve cylinder head to produce 134 horsepower and 247 pound-feet.
The result is a completely livable econobox. At the track, the TDI trails the slowest gasoline Jettas by more than a second, but with copious low-end torque routed through a responsive five-speed manumatic transmission, it tends to feel quicker than the 11.3-second 0-to-60-mph time suggests. Interestingly, that's exactly the time a fully charged '04 Toyota Prius hybrid needs to do the job. The two cars are closely matched in performance but utterly different in character. The Jetta's steering, brakes, and acceleration all feel like those of a conventional car, only a loudish 52-dBA idle clatter betraying it as a fuel sipper-there isn't even a fuel-economy gauge or computer available. The Prius goes about its parsimony a bit more overtly.
Bottom line: What little pain the Jetta TDI inflicts on drivability strikes us as well worth the gain in fuel economy.
