It's easy to forget how good the Audi A4 has been and for how long. The most recent generation has been around since 2009, and that does perhaps make the car's exterior styling seem a bit familiar. Then there's all-wheel drive, once an Audi specialty but now very common among luxury sedans. Yet when you really get down to it, the 2015 Audi A4 still has an impressively well-balanced portfolio of attributes.

While the A4 isn't as memorable to drive as some of its competitors, it still establishes a nice middle ground between your performance impulses and comfort needs. A 2.0-liter turbocharged four-cylinder engine provides the A4 with 220 horsepower. That's less than the BMW 328i, for example, but with 258 pound-feet of low-end torque on tap (slightly more than the 328i, actually), the A4 has no trouble getting away from stoplights or passing slower highway traffic. For those who need more, the superb 2015 Audi S4 performance model is just a heftier car payment away.

The A4's performance holds its own against its rivals, but the car's high-quality interior is where the car excels. Audi doesn't really do "trendy," and the A4's resulting clean lines, premium materials and pleasing accent lighting give the cabin a minimalist cool that makes some competitors' designs feel frumpy or look as if they're just trying too hard by comparison. Add to it a decently sized backseat and trunk and the Audi's cabin is suitably practical as well.

Fond of the Audi A4 though we are, it does compete against some awfully impressive small luxury sedans. The 2015 BMW 3 Series and all-new 2015 Mercedes-Benz C-Class are chief among them, offering similar refinement and driving experiences. The 2015 Acura TLX, 2015 Lexus IS and 2015 Volvo S60 are also compelling choices. Many of these competing models may be newer, more distinctively styled or offer a bit higher fuel economy. But the Edmunds.com "A" rated A4 continues to be one of the best small luxury sedans around.

The 2015 Audi A4 is a five-passenger sedan available in three trim levels: Premium, Premium Plus and Prestige. A4 shoppers who prefer a wagon can choose the Audi Allroad, which is effectively a wagon version of the A4. Those seeking more adrenalized thrills can opt for the higher-performance S4 sedan. Both are reviewed separately.

Standard features on the A4 Premium model include 17-inch wheels, xenon headlights, foglights, automatic wipers, a sunroof, cruise control, tri-zone automatic climate control, a tilt-and-telescoping steering wheel, eight-way power front seats (with four-way driver lumbar adjustment), a 60/40-split-folding rear seat, leather upholstery, Audi's MMI infotainment controller (dash-mounted), a 6.5-inch screen, Bluetooth phone connectivity and a 10-speaker sound system with a CD player, an auxiliary audio jack, an iPod interface and satellite radio.

Options include 18-inch alloy wheels, heated front seats and a navigation system with voice controls and console-mounted MMI controller.

The Premium Plus comes standard with 18-inch wheels, keyless ignition and entry, an auto-dimming rearview mirror, heated side mirrors, heated front seats and driver seat memory settings. Options include a 14-speaker Bang & Olufsen sound system and the Technology package, which bundles navigation, the console-mounted MMI, smartphone-integrated app services, Bluetooth audio connectivity, a rearview camera, a higher-resolution display screen, front and rear parking sensors and blind spot monitoring.

The Prestige model gets the Technology package and Bang & Olufsen sound system as standard equipment and adds adaptive headlights. Exclusive to the Prestige is the optional Driver Assist package, which adds adaptive cruise control, adaptive steering and Audi Drive Select (driver-selectable modes that adjust accelerator and transmission response and ride comfort settings).

Optional on both the Premium Plus and the Prestige is the Sport package, which adds a performance-tuned suspension, sport front seats and Audi Drive Select. The Sport Plus package raises the performance stakes with 19-inch wheels, high-performance tires, a sport steering wheel and gloss black exterior trim. You can also opt for the S Line and Audi Exclusive Line packages to fit your A4 with special exterior and interior trim details.

The 2015 Audi A4 uses a 2.0-liter turbocharged four-cylinder that produces 220 hp and 258 lb-ft of torque. Front-wheel drive and a continuously variable transmission (CVT) are standard, while all-wheel drive is available with either a six-speed manual or an eight-speed automatic transmission. Audi estimates that any of these powertrain variations will bring the A4 from zero to 60 mph in 6.2-6.6 seconds, which would be average times for this class.

EPA-estimated fuel economy is 27 mpg combined (24 city/32 highway) for the front-drive model. All-wheel drive and the manual transmission drop that slightly to 26 combined (22 city/32 highway), then further to 25 combined (22 city/31 highway) with AWD and the automatic.

The 2015 Audi A4 comes standard with antilock brakes, stability and traction control, front side airbags and full-length side curtain airbags. A blind spot warning system is optional on the Premium Plus and standard on the Prestige. Rear seat airbags are optional on all trims, while the Prestige can be equipped with an adaptive cruise control system that warns the driver and primes the brakes if it detects an impending collision. Front and rear parking sensors and a rearview camera are also optional.

In Edmunds brake testing, an A4 with summer tires came to a stop from 60 mph in 108 feet. This is excellent, though typical of a premium-brand car with summer tires.

In government crash tests, the A4 received a prefect five stars in every category, while the Insurance Institute for Highway Safety gave the A4 the best possible score of "Good" in the moderate-overlap frontal offset, side and roof-strength tests. However, it did receive the worst rating of "Poor" in the Institute's small-overlap frontal offset crash test.

What the 2015 Audi A4's turbocharged four-cylinder lacks in sonic personality, it makes up for in pleasant, punchy performance. It can still pin you to your seat when you put the gas pedal to the floor, and it offers ample torque for quick bursts of acceleration and highway merges. For drivers who crave more, the sport-focused S4 should more than suffice.

In standard form, the A4 is only slightly biased toward sporty and provides a pretty comfortable ride quality. Yet when the road bends, the A4 still feels balanced, secure and athletic. Opting for all-wheel drive further enhances the A4's capabilities and driver confidence, not to mention its stability in wet weather. More performance-minded drivers might consider the optional Sport and Sport Plus packages, although these come at the expense of a harsher ride quality.

With a sophisticated, modern design bordering on austere, the 2015 Audi A4's cabin is one of the best in its class. There's an air of adult seriousness here, reinforced by top-notch materials that reflect money well spent. Real leather upholstery as standard equipment helps distinguish the A4 compared with its BMW and Mercedes rivals, which use premium vinyl (that admittedly has wear and cleaning advantages).

Although the A4 is considered a small entry-level luxury car, the interior space is more akin to that of a midsize sedan. Front seat comfort is excellent, and the rear outboard seats provide enough head- and legroom to comfortably accommodate a typical adult. The 12.4-cubic-foot trunk is only average in size.

Entertainment and information functions are controlled by Audi's MMI, which is basically a dial controller surrounded by buttons that control menus on a central screen. It's an effective interface, even if some functions are nested deep within menu screens, but BMW's iDrive and Mercedes' COMAND systems are more intuitive. It's unlikely to be a deal-breaker, but does present a bit of a learning curve. Also, A4s without navigation place the MMI controller on the dash instead of the more convenient center console location.