With the introduction of the A5 for 2008, Audi launched itself into a vehicle segment it had never competed in – one which has waned significantly over the past two decades. Not so long ago, the personal luxury coupe was one of the top selling segments in the U.S., but for a wide variety of reasons, the overall sales picture left it behind.

Now you might ask yourself, "How is an A5 in any way similar to the likes of a 1970s-era Chevrolet Monte Carlo or Ford Thunderbird?" At first glance, the A5 is something completely different, but when you dig below the surface, there are more similarities than one might think – particularly when considering the 2.0T model. Except for a few NASCAR-inspired specials, PLCs of the 1970s weren't typically performance machines anyway – they focused more on style and creature comforts. And it's here where the A5 delivers.

Over the past two decades, Audi has been steadily climbing the ranks to become one of the preeminent automotive design houses. Concepts through the 1990s and the 2000s included the original TT and Nuvolari showed that Audi was capable of delivering more than bland German executive lunchboxes. The real explosion began when the first-generation TT entered production, and ever since, Audi's lineup has grown bolder with each successive model. The birth of the A5 brought mainstream Audi design to a whole new level, and it's fair to say that not only is this coupe is among the most attractive Audis in existence, it's probably one of the best looking coupes we've seen in decades.

While the high-powered S5 coupe and cabrio balance sophistication with performance, the reality is most A5s are powered by a much milder 2.0-liter TFSI inline-four. But that's not necessarily a bad thing. Larger coupes have almost always been more about style than substance, but all vehicle segments evolve over time, and the coupe market has proven no different. Over the years, mass-market brands looking to flesh out their lineups have embraced coupes as a way to add new variants of existing models without ballooning costs. The result was a proliferation of "coupes" that were often little more than two-door sedans that sacrificed ease of rear access without adding any real style. Worse yet, American personal luxury coupes became baroque and grotesque, and ultimately, a lack of substance contributed to their eventual demise.

We've become quite familiar with the A5's shape over the last several years and it's holding up incredibly well. Sharing the same mid-sized B8 platform as the A4 sedan/wagon and Q5 crossover, the A5 is clearly a modern Audi. However, the A5 has unique dimensions and proportions from its siblings, being lower, longer and wider than the A4 sedan, while riding on a shorter wheelbase. Combined with the 19-inch wheels, the overall effect is a more voluptuous effect than its sedan sibling.

The interior of the A5 will be instantly recognizable to anyone familiar with contemporary Audis. Two large primary gauges flank a central information display where the driver can page through an array of data. Everything from fuel economy to iPod tracks are directly in front to minimize looking away from the road. Our A5 tester was blessed with the Sport Package's optional front chairs, and their enhanced lateral bolstering and manually extendable thigh bolsters were more than welcome. The thick-rimmed steering wheel is grippy and adjustable for both reach and rake.

The racier roofline of the A5 means that the driver's hip point is commensurately lower. It's still nowhere near as sunken as the perches of most sports cars, but the A5 may not be ideal for those with mobility issues. As you might expect, access and accommodations in the rear seats aren't exactly commodious, although rear headroom is adequate (we managed to stuff a six-footer in back), anyone with longer-than-average legs may have an issue fitting comfortably in the back. At least there's a switch that motors the entire front seat forward, allowing rear passengers some latitude to control their own limited leg room.

While we are generally loathe to turn down more power, it makes sense to us that the best-selling member of the A5 family – by far – is powered by the Volkswagen Group's sweet 2.0-liter TFSI inline-four, putting out 211 horsepower and 256 pound-feet of torque. In this application, Audi's TFSI system includes a turbocharger and direct fuel injection, the latter of which allows the use of higher compression ratios and boost pressures without triggering piston-destroying knock. As a result, the relatively small engine can generate some serious torque over a broad rpm range, delivering power levels that would normally necessitate the application of a larger and less efficient engine.

A normally aspirated and direct-injected 3.2-liter V6 is also available, but while it produces 265 hp, it's down on torque to the inline-four with just 243 lb-ft. Further, the beefier powertrain adds an extra 200 pounds of heft, so you gain nothing over the four-cylinder model in performance and consume more fuel at the same time. With the extra weight hung out over the front axle, you also don't net anything in driver engagement, especially in North America, where V6 is paired exclusively with six-speed automatic transmission. The bottom line? Both models accelerate to 60 miles per hour in 6.4 seconds and you stand to have more fun getting there in the 2.0T, though one could certainly argue that the V6 makes a more appealing noise.

The best driver-oriented combination in the A5 family is also the least expensive – the four-pot paired with Audi's six-speed manual gearbox. The manual remains one of our favorites 'boxes thanks to its slick action and short throws. The clutch travel is smooth and predictable, making it easy to manage in stop-and-go traffic. Combined with the 2.0T's surprisingly robust torque curve, this combination provides some flexibility to drive in traffic without constantly rowing through the gears. The four-cylinder A5 may not win any drag races against some other sports coupes, but the DI turbo has more than enough grunt to instantly carry out passing maneuvers on a two-lane road without triggering any undue anxiety.

Another benefit of the entry-level drivetrain is its more desirable weight distribution. Along with the 40/60 front-rear torque split of the latest Quattro all-wheel-drive, there's remarkably little understeer compared to past Audis. Unlike the S4, the A5 doesn't feature Audi's trick torque vectoring rear differential, but buyers looking to push their coupe hard enough to notice will probably opt for the higher-performance model anyway. One thing every driver will notice, however, is the electro-hydraulic power steering assist. It's a tad light at low speeds, but firms up beautifully as speeds increase and has no disconcerting on-center dead zone.

Our A5 tester wasn't equipped with Audi's Drive Select, a system that includes variable damping and steering ratios, but it wasn't missed. On this model, the balance of spring and damping rates made trudging along the rough pavement of mid-Michigan a pleasure, without sacrificing dynamic responsiveness in the process. At 3,583 pounds, the A5 isn't a featherweight by any means, but Audi seems to have used the mass effectively to ensure it has built a solid structure. Even over the worst roads, the coupe remained tight and rattle-free.

With its graceful lines and classic proportions, the 2.0-liter A5 coupe really is the modern incarnation of the personal luxury coupe, albeit without the indulgent proportions, consumption and garishness of its 1970s antecedents. The A5 provides a great-looking ride for a couple while accommodating two more in a pinch. Its performance would have humbled pure sports cars not too long ago, and despite its small engine, even in moderately aggressive driving, it never feels like it's breathing hard. Even with little consideration for economy, our 2.0T-powered A5 returned a very respectable 25 miles per gallon in mixed driving.

As of mid-2010, Audi remains the only premium European brand offering four-cylinder engines in the U.S. market, and its consistent growth over the last several years indicates it may be on to something. Mercedes-Benz and BMW have both indicated that they will bring four-cylinder (and in BMW's case maybe even three-cylinder) engines back to their respective lineups in the coming years. You might think that a premium car with a four-banger might be just a loss-leader special, but Audi is showing it doesn't have to be so. At $44,750 including Premium, Sport and Navigation packages, the A5 is not inexpensive, but it's an attractive alternative to six-cylinder coupes like the BMW 3-Series, Cadillac CTS, Mercedes-Benz E350 and Infiniti G37, while providing better fuel economy to boot.

Click the title for the source