It’s not easy to stay on the Ward’s 10 Best Engines list. Each year we challenge a returning candidate in a different way and question whether it still is a benchmark.

For the third year in a row, Audi’s TFSI supercharged 3.0L V-6 has answered that question and continues to impress with stunning power, refinement and efficiency.

After testing it the past two years in the relatively small 3,637-lb. (1,650-kg) S4 with a 6-speed manual transmission, this year we evaluated the direct-injection V-6 in the larger 4,045-lb. (1,835-kg) A6 equipped with an 8-speed automatic transmission.

But the engine did not seem to notice the A6’s additional 400 lbs. (181 kg), even though it produces 310 hp in the A6 compared with 333 hp in the S4.

That’s because the engine still makes a prodigious 325 lb.-ft. (441 Nm) of torque available from 2,900 to 4,500 rpm. It delivers breathtakingly powerful acceleration when asked, yet remains supremely polished.

Once upon a time, nothing with fewer cylinders could match a V-8 in low-end torque unless it was a diesel.

Today, it is clear forced induction and gasoline direct injection can enable V-6s to beat larger displacement V-8s at their own game, delivering stump-pulling torque at lower engine speeds while offering superior fuel efficiency. In sophisticated autobahn burners like the S4 and A6, the 3.0L TFSI makes V-8s seem obsolete.

“Perhaps the most perfectly tuned vehicle in terms of NVH I’ve ever driven,” says WardsAuto editor Christie Schweinsberg.

With a 0-60 mph (97 km/h) time of 5.3 seconds, the A6 application is 0.4 seconds slower than the lighter S4. But thanks to the new 8-speed automatic, the bigger car actually gets better fuel economy, 19/28 mpg (12.4-8.4 L/100 km/) compared with 18/27 (13-8.7 L/100 km).   

It’s not difficult to get close to 30 mpg (7.8 L/100 km) on the highway, but our average over 258 miles (415 km) is 22.4 mpg (10.5 L/100 km). It would have been easy to have done better, but tipping into the supercharger’s boost is just so intoxicating we could not keep our right foot in check.

“One of the best of the best,” says WardsAuto editor Steve Finlay.

In addition to performance, the Audi V-6 sets the bar high in other areas as well. It demonstrates that supercharging still can compete with turbocharging as an induction strategy for mainstream vehicles (in addition to over-the-top performance models), and it shows that even a somewhat exotic engine can be flexible. It not only powers the S4 and A6, but the larger A7 5-door sedan and Q7 cross/utility vehicle.

The engine also is used in other brands belonging to Volkswagen, Audi’s parent, including versions of the VW Touareg, Porsche Cayenne and Panamera Hybrid.

With such a resume, this masterpiece of motivation had no trouble making the 2012 list. It will be interesting to see if it has such an easy time next year.

dwinter@wardsauto.com