Ward’s 10 Best Engines competition has recognized outstanding powertrains for 20 years. This installment of the 2014 Behind the 10 Best Engines series looks at the development of Audi’s TFSI Supercharged V-6.

It’s hard to believe this 3.0L boosted beauty – with no major changes or upgrades since its U.S. introduction in 2010 – snagged its fifth straight Ward's 10 Best Engines trophy for 2014. But those who know it as WardsAuto editors do understand it stays on their high-achievement list because it's so good that nothing else has supplanted it.

"No rivals have come along that can match the 3.0L's silkiness, its lively tip-in, its daily drivability, its gratifying torque at every engine speed," they say. "In other words, it's still a benchmark." Comments on their 2014 evaluation score sheets included: "One of the best high-performance V-6s ever," "the best engine I've ever encountered," and simply, "amazing!"

As tested in a ’14 S5 3.0 TFSI Quattro coupe, it delivers a grin-inducing 333 horses (111 hp/L) at 5,500 rpm, 325 lb.-ft. (441 Nm) of torque between 2,900 and 4,500 rpm and (according to Audi) impressive 4.9-sec. 0-60 mph (97 km/h) acceleration. Its only downside is fairly modest fuel economy at 17/26 mpg city/highway (13.8-9 L/100 km) and 20 mpg (11.7 L/100 km) combined, which correlates with the not-quite-20 mpg WardsAuto editors averaged in a total 415 miles (668 km) of driving.

The old V-8 it replaced for 2010 was less quick (typically 5-plus sec. 0-60 mph) and a lot less fuel efficient, so this supercharged 6-banger was a win-win on both fronts.

"During casual cruising," Executive Editor Tom Murphy writes, "the engine is supremely quiet, able to lull a small child gently to sleep. But [it] begs curious drivers to downshift and crack open a wide-open run for glory. They are not disappointed.... Some people consider V-8s a guilty pleasure. Think of the 3.0L TFSI as all pleasure, without the guilt."

While a turbocharger uses hot exhaust gas to spin a turbine that pumps more air into an engine, allowing it to burn more fuel and boost performance, a supercharger uses an engine-driven compressor. Generally more compact and less complex than a turbocharger, it provides instantaneous response but has the efficiency disadvantage of spinning at all engine speeds.

Based on an older 3.2L naturally aspirated V-6, this engine was substantially re-engineered to handle much higher output while increasing its efficiency.  Enhancements include a pressure- and volumetric flow-controlled oil pump, a reduced-friction chain drive and lower-friction piston rings.

Beyond strong acceleration and refinement, its primary design objective was to be versatile enough for use in nearly any Audi model. After testing twin-turbocharger and supercharged versions, Audi engineers decided on the latter for its better launch performance and compactness. Working with supplier Eaton engineers, they wedged it neatly into the 90-degree V of the cylinder banks.

Beyond compactness, it also requires few changes for different applications. It can operate happily with both manual and automatic transmissions, as well as with Audi Quattro all-wheel drive, and handle high towing loads in the Q7. And it does all this while meeting both U.S. ULEV2 and European EU5 emissions standards.

Surprisingly, it was planned as a small-volume engine for high-performance compact S4s and S5s. Now it is Audi's only V-6 available in midrange A6s and A7s, the flagship A8 sedan and Q5, SQ5 and Q7 CUVs. It’s also used throughout the Volkswagen empire for hybrid versions of VW's Touareg and Porsche's Cayenne and Panamera.

"It's a pretty hefty mix in all of these carlines," says Audi of America product manager Mark Fruechtnicht. "So it's a very important engine. It's very versatile and tunable to suit whatever vehicle it's in. It can represent a performance engine in an S4, S5 or SQ5, or a very nice, refined entry engine in an A8 or a Q model. It starts at 272 hp in the Q7 and goes all the way up to 354 hp in the SQ5."