Sporty performance and everyday luxury seldom harmonize in automobiles as angelically as they do in the 2013 Audi S4. Based on the A4 sedan, the S4 is a more raucous and enthusiast-bred interpretation of its housebroken counterpart. Its supercharged 3.0-liter V6 sends 333 horsepower to all four wheels, orchestrating a song of exhaust exclamations and plaintive tire degradation. With a sport-tuned suspension and stronger brakes, the S4 paints a perma-smile on the faces of all but the most Porsche-obsessed sports car fanatic.

That the fun comes without sacrificing comfort makes the S4 one of the best bargains shy of German rivals with sticker prices nearing six digits. The tasteful cabin is calm, quiet and feels like a hip, upscale hotel room (albeit one in Germany). The ride is compliant and brushes off road rumble with minimal jostle, and there's comfortable seating for four and a decent-size trunk.

The 2013 Audi S4 can seem a little pricey, but if you factor in its standard all-wheel drive and comprehensive standard features, it compares very well to the BMW 335i -- a sedan long considered the benchmark in the segment. Playing loose with the options list, however, puts the S4 in range of the Cadillac CTS-V and Mercedes-Benz C63 AMG, models that surpass the S4 in terms of performance and prestige. But even among such lofty rivals, the S4's all-wheel drive, refined surroundings and balanced nature make it a compelling choice.

The 2013 Audi S4 is the high-performance version of the regular A4 sedan. It's offered in a single Premium Plus trim level with an available option package known as the Prestige.

Standard features for the Premium Plus include 18-inch wheels, summer performance tires, a sunroof, automatic xenon headlights, LED daytime running lights, foglights, automatic wipers, tri-zone automatic climate control, heated eight-way power front sport seats (with four-way lumbar adjustment), driver memory settings, leather and simulated suede upholstery, a 60/40-split-folding rear seat, auto-dimming mirrors, Bluetooth phone connectivity, a dash-mounted MMI electronics controller and a 10-speaker sound system with a CD player, iPod interface and satellite radio.

The Prestige package adds adaptive xenon headlights, a rearview camera, keyless ignition/entry, rear parking sensors, voice controls, a 14-speaker Bang & Olufsen sound system, blind-spot monitoring, an MMI controller mounted on the center console, Bluetooth audio connectivity, Audi Connect smartphone integration, a navigation system and HD radio. If you don't want to pay for this entire package, the nav system and Bang & Olufsen stereo can be purchased separately.

Options exclusive to Audi S4s with the Prestige package include the Driver Assist package, which adds adaptive cruise control, an enhanced steering system and adjustable settings for engine,, transmission, steering and response (known as Audi Drive Select). A power rear sunshade and manual side shades are also optional.

Options available on all S4s include 19-inch wheels, adaptive suspension dampers, a sport rear differential (essentially a sophisticated limited-slip differential), full leather upholstery and rear-seat side airbags. Both the adaptive suspension and sport differential must be purchased in combination with Audi Drive Select, and doing so adds adjustable settings for the suspension to that menu.

The 2013 Audi S4 is powered by a supercharged 3.0-liter V6 that produces 333 hp and 325 pound-feet of torque. All-wheel drive and a six-speed manual transmission are standard, while a seven-speed dual-clutch automated manual (S tronic) is available and serves as the automatic-transmission option on this car. Audi offers what it calls an optional sport rear differential, essentially a limited-slip differential that helps apportion torque between the rear wheels to improve the car's cornering line. It's worth buying if you like to drive on twisty back roads.

In Edmunds testing, a manual-equipped S4 sprinted from zero to 60 in a quick 4.9 seconds. EPA-estimated fuel economy is above average for this class of car, with 17 mpg city/26 mpg highway and 20 mpg combined with the manual. The S tronic is rated 18/28/21.

Standard safety features for the 2013 Audi S4 include stability and traction control, antilock brakes, front side airbags and side curtain airbags. Rear-seat side airbags are optional, and the Prestige package adds a rearview camera, rear parking sensors and a blind-spot warning system. This package also allows you to add adaptive cruise control (at additional cost), and it includes a collision warning and mitigation feature that primes the brakes if it detects a possible frontal crash.

In Edmunds brake testing, the S4 stopped from 60 mph in 109 feet, an average distance for this class of car with summer tires.

Government crash test results aren't yet available, but the related A4 scored a perfect five-out-of-five stars for overall side-impact protection. In Insurance Institute for Highway Safety testing, the A4 earned a top rating of "Good" for its performance in the moderate-overlap frontal-offset, side-impact and roof-strength tests. The A4 earned a Poor rating (the lowest) in the Institute's new, small-overlap frontal-offset crash test, but only a handful of cars have been subjected to this test and a majority have earned low ratings.

As the hopped-up version of the already sporty A4 sedan, the 2013 Audi S4 is the performance-minded driver's choice. Handling is impressive, with tenacious AWD traction and little body roll. This cornering prowess does not come at the expense of comfort, either. Ride quality is still reasonably luxurious. For 2013, the S4 transitions to electric-assist steering, a move made largely to increase engine efficiency. We've yet to test the S4 with this new steering system.

The supercharged V6 is a smooth, strong engine with instantaneous throttle response. Aside from the subdued supercharger whine, you'd probably never guess there's forced induction going on under the hood. The standard manual transmission shifts smoothly, though its clutch travel and shifter throws are a bit long. The dual-clutch automated manual transmission, meanwhile, snaps off rapid shifts either by itself or through your own inputs via wheel-mounted shifters. Even if you're a serious driver, there's no shame in ordering this automatic option.

All modern Audis get high marks for interior quality, and the S4 is no exception. Seats, doors, panels and consoles are dressed with top-shelf materials in an austere and modern style. The front sport seats both comfort and cosset for long drives or short hops, but also wrap around the driver during more spirited dashes.

Infotainment functions are controlled by Audi's Multi Media Interface, or MMI. This consists of a small knob surrounded by buttons that together control menus on a central screen. Overall, it's an effective interface, though some audio functions are buried in menus and, in practice, we've found BMW's iDrive and Mercedes' COMAND systems a bit more intuitive to use. These MMI controls are located on the center console in S4s equipped with the navigation system, but cars without navigation have MMI on the dash, which is far less convenient. The S4's other controls are generally intuitive and well laid out.

Like the A4, the S4 features a roomy cabin that accommodates four adults comfortably, even for extended drives. At 12.4 cubic feet, trunk space is average for the class.