2013 Volkswagen Jetta TDI (diesel) with Premium and Nav: Fun and practicality.

Price: $27,215 as tested. An automatic TDI would start at $24,090. A six-speed manual begins at $22,990. (A gasoline S starts at $16,675, an SE at $18,995.)

Conventional wisdom: Diesels remain unpopular in the United States, even after ultra-low-sulfur blends were mandated in 2007. They had been rising in popularity until plateauing at about 2.8 percent of cars sold from 2011 through 2012, according to Edmunds.com.

Marketer's pitch: "Joyride from A to B, not A to filling station to B."

Reality: As fun as a gasoline-powered Jetta, with great mileage. And the quiet tap-tap-tapping of the diesel engine offered a more historically Volkswagen-like experience.

The perfect car? I've been wanting to spend a week with one of Volkswagen's unusual (for the States) turbodiesel small cars since I began "Driver's Seat."

Though Volkswagen currently has a corner on the low end of the diesel market, Mazda has unveiled a Mazda6 SkyActiv diesel that ought to give the Germans a run for their money later in 2013.

A Jetta Hybrid added for 2013 makes another choice for economy-minded Volkswagen fans, starting at $24,995.

Fuel economy: Let's start here; this is why we're even considering a diesel. The Jetta got 42 miles per gallon on the highway during my tests, and 38 around town. (Its average mileage resets automatically after the car is shut off for a certain period.)

Say it uses 10 gallons of fuel to go 420 miles; a gasoline Jetta would use about 15, according to an earlier "Driver's Seat" test. So using 33 percent less fuel more than makes up for the premium price of diesel (about 15 percent to 20 percent more per gallon).

The automaker tells me about 20 percent of Volkswagens sold are TDI models. And that percentage has held even as Volkswagen sales overall have jumped 35 percent.

T is for turbo, not turtle: I expected a lethargic ride, like the Volkswagen diesels of old. But I was surprised that the vehicle was peppy. It's no hot rod, but on-ramps were not frightening.

On the road: The Jetta TDI had all the road manners of its more refinery-palated gasoline cousin. Its handling was taut, and the car cornered and handled curves as well as any.

Friends and stuff: Again, it's a Jetta. The rear seat is spacious for its segment. The front seats are comfortable and easily adjusted. And trunk space? This car has loads. A nice, big glovebox, armrest storage for half a dozen CDs, and a good key fob/cellphone holder in front of the gearshift round out the package.

Cheap seats: Volkswagen is brave enough to send testers a stripped-down model. But 21-year-old Sturgis Kid 1.0 found the interior kind of cheap-looking. And I admit the plastic dashboard, with its rectangular heater vents, is not going to win any beauty contests.

While the rear window seats are comfortable, anyone caught in the middle has a fairly large hump to contend with.

Easy controls: Volkswagen has made everything easy to find. I'm partial to the three-knob heater controls, simple radio functions, and easy-to-understand gauges.

Where it's built: Puebla, Mexico.

How it's built: Consumer Reports says first-year reliability ratings of the diesel version are below average.

In the end: I've met many people over the years who have been loyal buyers of Volkswagen's diesel models, and their cars were consistently racking up 200,000 and 300,000 miles in the days when most odometers had just five digits.

The fun of the Jetta made me that think someday I'll be in that merry band as well, but I think I'd much rather do it in a Passat TDI. Here's hoping that model's Tennessee roots bring it increased reliability.