Wednesday September 26, 2012

MANCHESTER -- Want chart-topping fuel economy but can’t stomach the panacea of an electric-gasoline hybrid? Try a diesel, or to be more specific, one of Volkswagen’s TDI (Turbo Direct Injection) clean diesels.

An invention of German engineer Rudolf Christian Karl Diesel, the typical diesel engine is built to a higher compression ratio compared to its gasoline-burning counterpart resulting in higher thermal efficiency (eking out more energy per gallon of fuel) and greater torque (the actual output of the engine). This accounts for greater fuel economy: Volkswagen touts up to 30 percent better with its TDIs compared to their gasoline equivalents.

While more thrifty, Americans’ views of diesel power have long been tinged by dismal 1970s soot-belchers and smelly big rigs, and as a result they comprise just one percent of passenger vehicle sales in the United States, excluding light trucks. Compare that to over half of all passenger vehicle sales in Western Europe today.

A large part of the problem has been simple lack of availability stateside. But as fuel prices remain high and each automaker attempts to outdo one another in the Miles Per Gallon category, Volkswagen’s gambit in 2012 involves pitching the diesel as a viable, even advantageous, option for better economy in the family hauler. It can be "green," too -- Diesel’s demonstration unit at the 1900 world’s fair in Paris ran on peanut


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oil.

One of the sole manufacturers to continually offer diesel passenger vehicles in the U.S., Volkswagen hopes diesel will comprise a large percentage of its future growth strategy. To wit, the German automaker now gives the U.S. market the option of a diesel in six of its most popular models, from the compact Golf up the line to the Touareg crossover. With better economy offsetting the difference in price at the pump, the new generation of diesel engine is quieter, too, more refined and emitting less emissions courtesy of advances like the introduction of ultra-low-sulfur fuel in 2006.

All of which brings us to the 2012 Volkswagen Jetta TDI SportWagen, an exemplary (re)introduction to the world of diesel. Spooked by the phrase "glow plug"? Think urea is an anatomical term? Don’t worry, the dash light for the glow plug winks out in an instant when you turn the key, and the car is clean enough to not require the latter fuel additive. With civil manners and torquey grunt, the TDI SportWagen is easy to live with, and possibly the biggest adjustment moving into one may be remembering which pump to pull up to when it comes time for a re-fill.

The present-day Volkswagen TDI is a turbocharged, 2.0liter in-line four-cylinder producing 140 horsepower and a stout 236 pound-feet of torque -- Rudolf would be proud. While I experienced the most utilitarian diesel, the wagon, the engine is the same throughout the rest of the available TDIs (the exception being the 2013 Touareg.) So how does it perform? Forty miles to the gallon has never been this fun. Curiously, the U.S. Environmental Protection Agency’s test cycle appears to undervalue diesel economy, as the TDI SportWagen’s fuel economy estimates (as seen on the window sticker) are set at 29 MPG city, 39 MPG highway.

Over the course of the first 100 miles with my test vehicle, the Volkswagen’s on-board computer displayed 38 MPG in mixed driving over mostly backroads with no thought toward economy. Reset for the remainder of the time and given less throttle, the car returned 42 MPG.

For the best results, hit the interstate and set the cruise -- the sales staff at Hand Motors in Manchester relay feedback from TDI owners of highway mileage ranging into the 50s. Wunderbar! The benefit of diesel versus gasoline-electric hybrid is especially evident in the Northeast where half of the time it’s cold, and most of the driving is on open roads, not stop-and-go city traffic. Economy aside, it’s an apples to oranges comparison when you factor performance.

Peak torque (236 lb.-ft., remember?) is produced way down in the TDI’s powerband -- at 1,750 revolutions per minute. For comparison purposes, your milquetoast hybrid delivers basically equivalent economy, in the low 40s mixed, but their powerplants are way down on power resulting in a soporific right pedal. The TDI SportWagen hauls when goosed. While there’s a slight discernible difference at idle, there’s no undue vibration or harshness, engine response is good, and there’s little indication driving that the car burns anything other than petrol. The sole exception might be light throttle response in low speed, parking lot situations, or else while pedaling slowly from an intersection. For whatever reason there’s that flat spot down low, but it’s easy to grow accustomed to with a little extra throttle.

As-tested, my vehicle came with Volkswagen’s DSG (Direct Shift Gearbox) transmission, which deserves some ink in its own right.

First introduced in 2003, the DSG is truthfully a sixspeed manual transmission, with two clutches but sans clutch pedal. A computer shifts instead, quicker than any human driver: Less than four-hundredths of a second. DSG-equipped vehicles feature two driving modes, a normal and "Sport," and also allow drivers to shift manually via the gear lever. Some Volkswagens (like the GTI) include steering wheelmounted paddle shifters -- not so on the TDI SportWagen.

The DSG marries the benefits of both manual and traditional automatic (it’s lighter than an auto, there’s no clutch pedal), and it’s typically "bulletproof," although it has been the subject of recall. Overall it’s phenomenal, and typically the only option on the lot. Traditionalists can factory order a six-speed manual.

The Jetta was last made over for 2010, and the current generation simply feels grown up from the previous iteration, with most of the exterior changes going toward the refreshed front end. The lines are muscular but wellproportioned, and the wagon configuration offers plenty of cargo space (and rear passenger headroom for our gangly rear passengers). Contrasted with the latest flamboyant designs from South Korea, Volkswagen exudes Teutonic restraint. Convenience-wise, the TDI SportWagen includes the features of the upper SE trim gasoline car, accounting for about half the difference in price between the TDI and base SportWagen. Inside, interior materials feel top notch and the panoramic sunroof allows lots of light, giving the cockpit an open, airy feeling. The control knob for the sunroof has easy detents to crack the window open in small increments, or a single twist fully slides it open. The seats are wide, comfortable slabs that offer a tall position; doubly so in the rear.

In terms of Bluetooth and cell phone integration, Volkswagen has hands-free down pat. Once paired, the vehicle automatically connects to your phone on startup, with the instrument panel screen displaying the phone’s connection, battery life, service provider and reception. (Regrettably the SportWagen can do nothing for the latter.) Dialing a number is safely accomplished on the in-dash touch-screen display, or there are voice commands thrown in as well.

Traveling down the road, the SportWagen’s suspension strikes a great balance between dampening bumps and communicating road feel without excess body roll. The chubby steering wheel is well proportioned for the car’s steering, and although there’s a skittishness over bumpy pavement, the wagon handles its extra girth well. It’s responsive enough to be a pleasurable drive; although the trade-off to all that utility is that it’s a magnitude less sporting than the smaller Golf or GTI.

The Manufacturer’s Suggested Retail Price for the 2012 TDI SportWagen as-tested totaled $28,390, which includes a premium for the DSG. Feature-for-feature, the diesel carries a $2,475 premium over the gasoline Sport-Wagen, which the average driver would recoup from fuel savings over several years of ownership. Diesel used to be priced below gasoline, but global demand and production and distribution costs have caused prices to invert in recent years.

Zeke Wright is a reporter for the Bennington Banner and a noted car enthusiast.