In the ongoing horsepower war raging among luxury brands, the 2011 Audi A4 has essentially declared itself neutral, the automotive equivalent of Switzerland. While others from around the world duke it out with six-cylinders and ever-increasing power numbers, the A4 makes due with a turbocharged four-cylinder good for only 211 horses. This might seem as if Audi is deliberately limiting the A4's appeal, but in reality the A4 manages to nearly match (or better) the acceleration of its competitors while simultaneously offering impressive fuel economy and the reassurance of available all-wheel drive.

The A4 has never really been known for its performance, though. Instead, it has been (and continues to be) a car defined by a high-quality interior, one that's typically the benchmark in its class. While perhaps not as visually interesting as some of its competitors, the A4's typically German cabin nevertheless has a rich ambiance. Add to it a decent-sized backseat and trunk and the A4's cabin is suitably practical as well. The A4 Avant wagon isn't exceptionally roomy, but it does give you more versatility than the sedan can manage. Plus, it looks pretty darn snazzy with its aggressively tapered roof line.

In terms of driving, the A4 does a commendable job of balancing ride and handling, placing it somewhere in the middle (neutral once again!) of the comfort-to-sport spectrum. Should you desire a more aggressively tuned car, one of several available sport packages should tighten up the A4 to your liking. If that still isn't enough and if you're seeking more power, Audi offers the higher-performance S4 sedan (reviewed separately), which we've found to be a more compelling driver's car than a BMW 335i.

As you can tell, we're fans of the 2011 Audi A4 -- especially the Avant. However, in its class are several highly acclaimed rivals. The 2011 BMW 3 Series is the popular rock star that's more compelling to drive. The 2011 Mercedes-Benz C-Class is an impeccably built stalwart, while the overachieving Infiniti G37 boasts far more power for the same amount of money. Even the 2011 Volkswagen CC is probably worth a look. But if you're OK sitting on the sidelines of the horsepower war, sticking with the A4 is an excellent choice.

The 2011 Audi A4 is available in sedan and wagon (Avant) body styles. Both come in Premium, Premium Plus and Prestige body styles.

The Premium trim comes standard with 17-inch alloy wheels, a sunroof (panoramic on Avant), cruise control, foglamps, automatic climate control, eight-way power front seats, a tilt-and-telescoping leather-wrapped steering wheel, leather upholstery, a dash-mounted Audi Multi Media Interface (MMI) and a 10-speaker sound system with a CD player, auxiliary audio jack and satellite radio. Options on the Premium include heated front seats, Bluetooth and an iPod interface.

These items come standard on the Premium Plus, which further adds automatic bi-xenon headlights, LED running lights, automatic wipers, three-zone automatic climate control, an auto-dimming mirror and an enhanced trip computer. The Navigation package adds a navigation system with real-time traffic, digital music storage, a more user-friendly console-mounted MMI system, a rearview camera, rear parking sensors, voice controls, HD radio and a color trip computer screen.

The A4 Prestige comes standard with 18-inch wheels, keyless ignition/entry, driver memory settings, auto-dimming exterior mirrors, the Navigation package and a Bang & Olufsen premium sound system (optional on Premium Plus). The Avant Prestige gets a power tailgate. Options unique to the Prestige include a blind-spot warning system, the Drive Select package (which provides adjustable settings for the suspension, steering and transmission), adaptive cruise control, a power rear sunshade and manual rear side sunshades.

The Sport package includes 18-inch wheels on the Premium Plus (19-inch wheels on the Prestige), a sport-tuned suspension, a three-spoke steering wheel, more aggressively bolstered seats and automatic transmission shift paddles. The S Line package available on the Prestige only is essentially a Sport package with faux-suede seat inserts and special exterior and interior trim. The Titanium Sport package available on the Premium Plus and Prestige is essentially a Sport package with some darkened trim and 19-inch wheels.

Every 2011 Audi A4 is powered by a 2.0-liter turbocharged four-cylinder that produces 211 horsepower and an ample 258 pound-feet of torque. The sedan's Premium and Premium Plus trim levels come standard as the 2.0T FrontTrak, indicating it has front-wheel drive and a continuously variable automatic transmission (CVT). All trims can be had as the 2.0T Quattro, denoting all-wheel drive and either a standard six-speed manual or optional eight-speed automatic. The Avant is available only with Quattro and the automatic.

We have yet to test an A4 with the new eight-speed automatic, but the old six-speed unit contributed to a decent 0-60 time of 6.5 seconds. EPA-estimated fuel economy for the 2.0T FrontTrak is 22 mpg city/30 mpg highway and 25 mpg combined -- very frugal for a luxury sedan. The 2.0T Quattro achieves a still-impressive estimated 21/29/24 with the automatic and 21/31/25 with the manual.

The 2011 Audi A4 comes standard with antilock brakes, traction and stability control, front seat side airbags and side curtain airbags. Rear-seat side airbags are optional on the Premium Plus and Prestige, while a blind-spot warning system is optional on the Prestige. Also available is an "Active Braking Guard" feature that's part of the adaptive cruise control optional on the Prestige. If an imminent collision is detected, the system alerts the driver and primes the brakes for full stopping power.

In the government's new, more strenuous crash testing for 2011, the A4 earned an overall rating of four stars out of a possible five, with four stars for overall frontal crash protection and five stars for overall side crash protection. In Insurance Institute for Highway Safety crash tests, the A4 earned perfect ratings of "Good" in both frontal-offset and side impact crash testing, and that was without the optional rear-seat airbags.

In Edmunds brake testing, an A4 Avant with the Sport package came to a stop from 60 mph in an astoundingly short 103 feet -- about the same as a Porsche 911. Without the Sport package, an A4 Quattro sedan stopped in an average but still acceptable 123 feet.

The 2011 Audi A4's handling is neutral and secure, especially when equipped with the all-wheel-drive system. It becomes downright athletic when you add the Sport package, though ride quality suffers (especially with the 19-inch wheels).

The turbocharged four-cylinder engine is a mixed bag. It gives the A4 class-competitive acceleration, but it doesn't sound as refined as a six-cylinder, and transmits some off-putting vibrations through the steering wheel.

Also of note is the optional Audi Drive Select system, which allows the driver to choose among three modes for ride compliance, steering effort and transmission responsiveness -- or enjoy custom settings via a fourth "Individual" mode. It's an interesting but pricey idea, and in testing we've noted it creates more drawbacks than solutions. Most shoppers should find the A4's standard suspension, steering and transmission calibrations perfectly adequate.

The 2010 A4's cabin is one of the nicest in its class. Surfaces are soft and nicely textured, while the standard leather upholstery trumps the vinyl leatherette in base-model BMWs and Benzes. The controls for most infotainment functions (dubbed MMI) are conveniently arrayed around the shift lever on models equipped with the navigation system, but cars without navigation have MMI on the dash, which is a much less convenient location. Navigation-equipped cars also get the newer, improved version of MMI. The A4's other controls are generally intuitive and well laid out, though accessing certain features can be an exercise in frustration. Adjusting something as simple as the fan speed, for example, is a two-step process.

The sedan's 12-cubic-foot trunk is average in size, so it's worth considering the Avant, as it offers 17.3 cubic feet. Fold the Avant's seatbacks down and you've got 51 cubic feet: a useful amount, though it is below average for a wagon because of the Audi's rakish rear-end styling.