It is not often that an automaker tries to combine "high-mileage fuel economy," "entertaining driving" and "luxury" in one vehicle. But those guys at Audi are giving it a shot with the diesel-powered A3 TDI, rated at 30 mpg city and 42 highway.

If the A3 doesn't ring any vehicular bells, it is a small, four-door hatchback. If you are more familiar with Volkswagens than Audis, the A3 is almost 4 inches longer than the Golf, a sibling. But it has a big-car price.

The A3 TDI starts at $30,775 with front-wheel-drive; the diesel is not available in all-wheel-drive. That is $1,200 more than an A3 with the gas engine. The TDI tested had a long list of options ranging from a navigation system to the twin "Open Sky" sunroof, bringing the sticker to $37,425.

But after some time driving, the shock of that price diminishes as the awareness of the fun of driving a diesel increases. This is not, however, a traditional diesel. This 2-liter 4-cylinder is a high-tech, turbocharged, direct injection (hence TDI) diesel. And it works with Audi's excellent, fast-shifting six-speed S-Tronic automatic.

The diesel has only 140 horsepower but it makes up for that with 236 pound-feet of torque, all of which is available at only 1,750 rpm. In ordinary language, that's very quick response. Brake for a sharp turn, prudently ease through a blind corner and, when you're ready, the little diesel rushes you forward.

TDI's forward progress is determined, but not fast. Audi says it takes 9.1 seconds to reach 60 mph, which is about 2 seconds slower than the A3 with the 200-hp gas powerplant. But the diesel's responsiveness makes it surprisingly satisfying with the far better fuel economy a bonus — as long as the price of diesel stays close to that of gas.

In the supporting role is the suspension, facing the classic challenge of providing good handling and reasonable comfort in a small car.

Most of the time the A3 TDI is eager, but on a slow, tight turn the weight of the front-wheel-drive can make it feel a little nose-heavy. The ride is generally tolerable until you hit a bad road surface. Then, it's jolting. Minor complaints: The steering is oddly light at low speeds but feels good above 40 mph or so, and the brake pedal is slightly soft.

The interior has a low-key elegance, though the all-black on the test vehicle struck me as a bit somber. The twin sunroofs do help somewhat. The basic controls are logical, and there's adequate storage. One downside is a fair amount of road noise, but none of it diesel clatter.

With two large adults upfront, the back seat is fit for only young kids or teens being punished for real or imagined sins. It is best to think of the A3 as a small wagon for two. Fold down the back seat, and Audi says there is 39 cubic feet of cargo space. That's three times as much as the trunk of the A4 sedan.

All the important safety gear is standard and, after a series of crash tests, the Insurance Institute for Highway Safety gave the A3 a "top safety pick" label.

So, what to do? The common-sense, less-indulgent choice would be to buy a Volkswagen Golf TDI. It gets identical mileage, is slightly faster and while not nearly as luxurious would save at least $5,000. Until emotion gets in the way. There is an almost counterculture joy to driving the A3 TDI — for those with the money.

E-mail Christopher Jensen at transportation@tribune.com.