Review

Introduction
The Audi A4 must be doing something right. The sedan version alone sells more than 40,000 units annually in the U.S., while competing against the Mercedes-Benz C-Class, BMW 3 Series, and a growing list of domestic and Asian rivals. In a segment where engineering excellence sells cars, Audi claims the turbo-four A4 delivers best-in-class fuel economy, while posting quicker 0-60 mph acceleration times than six-cylinder, all-wheel-drive competitors such as the BMW 328iX, Mercedes-Benz C300 4Matic, and Lexus IS250 AWD. The A4 also has on average more passenger room than the BMW 328, Mercedes C300, or Lexus IS250.

Audi completely redesigned the A4 for 2009, and this latest generation is as closely related to the recent A5 coupe and cabriolet as to the previous A4 sedan. At once familiar as an Audi yet obviously new, the A4 was changed most in ways you can't see. The current A4 is wider and longer but no taller than its predecessor. It's larger inside with the most notable improvement to rear-seat legroom, and it has a more usable trunk that is easier to load. A large increase in wheelbase, which is more than six inches longer than before, increases cabin space and improves ride quality and handling. And an adjustable suspension similar to that used on larger Audis is now available.

Despite its modest size the A4 comes well-equipped with leather, moonroof and automatic climate control as standard. Features normally associated with big luxury cars are available, such as adaptive cruise control, lane departure warning and a half-kilowatt surround-sound system.

2010 A4 Prestige models come with voice-control navigation, and all navigation-equipped A4's feature third-generation MMI (Audi's Multi-Media Interface) and Sirius traffic updates. A Bang & Olufsen audio system is optional on Premium Plus as well as Prestige models; and Premium models package Bluetooth and Homelink as a single option.

All three 2010 A4 trim levels (Premium, Premium Plus, and Prestige) now share the same engine, a 211-horsepower 2.0-liter turbocharged inline-four. Sedans are available with front-wheel drive and a CVT automatic; or all-wheel drive with either a six-speed manual or six-speed Tiptronic automatic. The A4 Avant station wagon comes exclusively with the six-speed automatic and quattro all-wheel drive, and so it starts at a somewhat higher price. EPA ratings range from 18/27 to 23/30 mpg.

For 2010, Audi has re-introduced the truly high-performance S4 sedan, packing a supercharged 3.0-liter V6 positively rippling with 333 horsepower and 325 pound-feet of torque; and pawing the pavement through a rear-biased quattro all-wheel-drive and 18-inch wheels. Unique appearance items inside and out guarantee that neither you nor your neighbors will forget what you're driving.

We've found these latest A4 models a delight to drive. They are compliant enough to soak up bumps like a larger car but firm enough to feel solid and stable to its (electronically limited) top speed of 130 mph. This latest-generation A4 rides like a larger car than did the pre-2009 models, but it also handles better than it did before. The front-drive A4 is not as delicately precise as a rear-drive 3 Series. But the quattro holds its own against the other all-wheel-drive cars. It more than holds its own in the rain against other sporty cars as well.

Line-Up
The 2010 Audi A4 is available as a four-door sedan or wagon (which Audi calls the Avant). The high-performance S4 is offered as a sedan only.

The A4 2.0T Premium sedan ($31,450) is the entry-level model, and comes with a 2.0-liter, 211-horsepower turbocharged four-cylinder engine, continuously variable transmission (CVT), front-wheel drive, and speed-variable Servotronic power steering. Also standard are AM/FM/CD audio with auxiliary input and Sirius Satellite radio, single-zone automatic climate control, cruise control, leather-wrapped steering wheel with redundant controls, leather seats with power adjustment up front, aluminum interior trim, split folding rear seat, sunroof, fog lamps, alarm, and 17-inch wheels.

The A4 2.0T quattro Premium sedan ($32,350) is equipped similarly, but with all-wheel drive and six-speed manual transmission. A six-speed Tiptronic automatic is optional ($1,200). Yet another variation is the A4 2.0T quattro Premium Avant ($35,350), an all-wheel-drive wagon with Tiptronic transmission. The Avant comes standard with the Open Sky panoramic sunroof.

The Premium Plus package ($3,550) for all the above models adds three-zone climate control, iPod and Bluetooth interfaces, heated front seats, driver information display, Homelink, rain-sensing wipers, automatic xenon headlights, LED running lamps and taillamps, and chrome window trim. A Sport package ($1,450) adds 18-inch road wheels, three-spoke steering wheel (with shift paddles on automatic cars) and sport seats and suspension. Other options include heated front seats ($450), iPod interface ($300), Bluetooth/Homelink package ($700), dark walnut or almond beige ash interior trim ($400), floor mats ($200) and exhaust tips ($130). Offered only with the Premium Plus package is a Bang & Olufsen stereo ($850); the 18-inch wheels and tires without the Sport package ($800); and a navigation system with 3G MMI, voice control, rear parking sensors, rearview camera, and color display ($2,500).

The Prestige package ($9,200) includes 18-inch wheels, the Bang & Olufsen stereo with DVD player, advanced keyless starting, auto-dimming mirrors inside and out, memory for driver's seat and mirrors, compass, and voice-control navigation with 3G MMI. The Driver Assist package ($800) with lane change assistant, rear parking sensors and rearview camera; 18-inch chrome wheels with summer-performance tires ($850); adaptive cruise control ($2,100); the Drive Select package ($2,950) with driver-adjustable adaptive steering and suspension damping; the S-Line package ($2,450) with sport seats featuring Alcantara inserts, brushed aluminum interior trim, black headliner, unique bumpers and side sills, sport suspension and performance tires on 19-inch wheels; and sunshades for the rear and rear-door windows ($500).

The S4 quattro sedan, powered by a 333-horsepower supercharged 3.0-liter V6, and available with six-speed manual ($45,900) or seven-speed S tronic automatic ($47,300) transmission. Standard trim for the S4 is Premium Plus; also standard are high-performance tires on 18-inch wheels and S4-specific steering and suspension. Prestige trim ($6,100) in this case includes all of the A4's Prestige goodies plus 19-inch wheels. Choose the Driver Select package ($3,950) for S4, and you can also opt for an electronically controlled rear differential ($1,100) which communicates with the Driver Select electronics. Exclusive interior options includes Silk Nappa leather seats ($1,000) and Carbon Atlas ($500), Stainless & Piano Black($750), or gray birch ($500) inlay panels. Otherwise options are similar to A4, albeit sometimes priced higher.

Safety features for all A4s include two-stage driver and adaptive passenger frontal airbags, side-impact airbags, curtain airbags, driver knee airbag, Backguard headrests; electronic stability control, ABS, EBD, Brake Assist, and tire pressure monitors. Rear side-impact airbags are optional ($350) on all models. As noted above, adaptive cruise control, lane departure warning, rear camera, and park assist are included in specific option packages; and quattros are equipped with all-wheel drive.

Walk Around
The latest A4 looks wider, lower and longer than the previous generation (pre-2009), in part because it is wider and longer without being taller, and in part because the front end is shorter, crisper, leaner and more tapered. It shares the split-grille common to all front-engine Audis, with points on the lower air dam that mimic crab pincers. The headlamp housings are boldly horizontal, and the light elements themselves draw the eye up and back at the corners.

The wheelbase, the space between the front and rear axles, is 110.6 inches, long by compact sedan standards. To minimize any limousine look the lower character line along the doors sweeps progressively upward toward the rear wheel, and the shoulder character line just below the windows tapers off as it passes the rear door and curves through the taillight lens as it fades in to the fender. Aerodynamics have been improved by 3 percent despite the wider dimensions.

When equipped with the bi-Xenon headlights and LED daytime running lights, the A4 looks a bit meaner, especially when the daytime running lights are on (on any A4 the daytime running lights can be enabled/disabled through MMI). They also provide better nighttime vision for the A4 driver (including speed-dependent adjustment) and make the A4 stand out so other drivers see it sooner.

Premiums ride on seven-spoke wheels, Premium Plusses on ten-spokers, but both measure the same 17-inches and wear all-season tires. S-Line models add a silver center blade below the grille; sleeker air intakes; side skirts; and finer, seven-double-spoke wheels to give the A4 a more imposing, hunkered-down stance.

The A4 Avant is as aerodynamic as the previous-generation A4 sedan, and while wagons aren't as slick as sedans, wind noise is absent. Rear visibility is good in the Avant thanks to the rear wiper/washer and the added internal volume means the rear window doesn't fog as quickly.

Horizontally themed tail light housings frame the rear end; for 2010, Premium Plus and Prestige models sport LED taillights to complement their LED front running lights. The trunk and cargo hatch openings are slightly closer to the ground than in previous generation models for easier loading. Avants are rated to carry 198 pounds on the roof, more than many SUVs because of the A4's lower center of gravity.

Of course the S4 has a look all its own. The standard model's blacked-out, horizontally themed two-tier grille is overlaid with strong verticals that visually transform a mere opening into a grid. On the other hand, the much-smaller slot below the grille is blacked out on the S4 (rather than divided by four body-color verticals as on the A4) and its bottom edge is defined by an aluminum diffuser blade. A red/silver/black S4 badge appears within the main grille, offset to the curb side. The S4 front fascia is unique as well, with the horizontal bumper segments to either side of grille recessed to make the central grille appear more prominent, although, honestly, this difference is so slight as to leave us wondering if it was worth the tooling cost.

A thankfully subtle rib below the door openings suffices for a side-sill extension; kudos to Audi for under-doing what so many other automakers over-do. More distinctive are the S4 Prestige model's 19-inch wheels with their five triple-ribbed spokes. Around back, the rear bumper fascia gains some crispness from a raised lower border where it arches over those two pairs of exhaust outlets separated by another aluminum diffuser blade. Outside mirror housings are aluminum as well.

Interior
Any recent Audi owner will find the A4 interior familiar, though some of the basic black German efficiency has given way to a warmer, more contemporary cabin a bit north of Germany into Scandinavian territory. Unlike its C-Class and 3 Series competitors, leather upholstery is standard in every A4, and the fit and finish match recent Audis commonly used as benchmarks.

Front seats are electrically adjusted with four-way power lumbar support for the driver and manual headrests that adjust for height but not angle (for safety reasons). With generous travel in the tilt-and-telescoping steering column everyone should be both comfortable and properly positioned for driving, and seat support will easily last a tank of fuel on the highway. The sport seats in S-Line or Sport packages are even better at keeping you secure without taking away any comfort; only those of wide girth may prefer the less-bolstered standard seat. A driver memory system for seat and mirrors is available.

The rear seat is best for two adults or three kids; the center floor hump and console are similar to what you find in most compact four-doors. Seat cushions are pleasantly long and the low-profile headrests on the back seats ensure good rearward vision without passengers yet lift enough to provide passenger comfort and protection. A substantial center armrest offers cupholders and storage within, and doesn't make you fall inward or outward to relax on one arm. The split backrest folds with the narrow part behind the driver, each released by a simple latch without first removing a headrest.

Rear seat reading lights and seatback nets are standard, as are LED footwell lights for the toe room under the front seats. Last year's redesign added almost and inch and a half to rear seat knee room, though in anything but full-size cars this is typically a pinch point.

There are some exceptions (IS front legroom, 3 Series and C-Class rear width) but on average, the A4 offers better head, leg and shoulder room than its primary competitors. The standard moonroof and the big Open Sky roof on Avants let in light and offer the illusion of more spaciousness.

Light-colored cabins have complementary trim colors, with a lighter shade for seats, door insert panels and headliner; and darker shades on the dash, door edges and armrests, and carpeting. A metallic-look trim is the default, though genuine wood (a light honey-colored almond ash or darker walnut) for the glovebox, console and doors may be specified. It's unlikely you will find a more appealing interior at the price.

Seats in the S4 have Alcantara inserts and embossed S4 logos. Contrasting stitching also highlights the seats, as well as the leather-covered shifter and steering wheel. Standard interior trim is brushed aluminum; options include stainless steel, carbon fiber, and gray birchwood.

The A4 driver faces a dashboard modeled after other recent Audis, with the console slightly tilted left and center dash angled toward the driver and carried to the same height as the instrument pod; passengers can still reach those controls but it flows to the driver so much better. The center armrest top slides fore/aft and all the controls are within easy reach, the ergonomics faultless. We would prefer the gate for the manual mode on the automatic transmission shifter on the left side (closer to driver) than the right, however.

Large dials provide speed and engine revs, with 0 straight down; you may have to recalibrate your mental clock positions for the speedometer needle; and the mid-range of the tachometer may be obscured if you lower the tilt wheel too far (and you'll mask the warning light pod top center). However, with everything properly positioned, all instruments are clearly visible and well lit at night, with deep amber lighting to preserve eye recovery time. Between the two primary gauges is a message center for gear selected and engaged, radio data, range remaining, outside temperature and so forth. On higher-level cars trip computer data, cruise control distances, and navigation data are shown here as well.

At the same height and to the right is a 6.5-inch color screen. On non-navigation cars this does radio, some climate and car setup chores (beep with alarm, unlock driver door only, etc.). On non-navi cars the MMI (multimedia interface) command dial is in the center of the radio panel just below the vents, and it and the similar control for climate immediately below it are illustrated on the screen.

On navigation-equipped cars the MMI is ahead of the shifter (or behind it from the driver's point of view). It maintains the eight hard key choices as before and remains among the more intuitive-type systems; the upgrades to the voice-recognition navigation system only make it easier and quicker. With this setup the radio panel reverts to a CD control panel, the screen is larger and it includes a backup camera. Many of the audio and setup controls can be run through the thumbwheels on the steering wheel that both rotate and push-to-click.

Automatic climate control with full manual ability is standard on the Premium model; it kept a black wagon's occupants comfortable in desert sunshine. On Premium Plus and Prestige models, three-zone climate control gives independent control to each front occupant and places a pair of vents with temperature gradient in the back of the center console. Rear window shades are optional (with the Prestige Package) if you prefer to avoid aftermarket tint.

The standard audio system handles most inputs. But for the best in sound entertainment, pop for the Bang & Olufsen system, which backs up some added visual drama with 14 speakers fed 10 distinct channels and 505 watts of output. (Last year's mid-range Symphony system is no longer offered.)

With all that packed into a small four-door, storage spaces are at a premium. Each door has a map pocket that will hold a bottle, both center armrests have small bins, seatbacks have net pockets, and the surprising glovebox can hold more than some papers and the owner's manual. Beyond that, you're headed to the trunk.

Trunk space, which Audi listed as 16.9 cubic feet in 2009, has been mysteriously down-rated to just 12.0 cubic feet for 2010; although as far as we can tell it's the same trunk. The new number is about the same as for a BMW 3 Series and a little smaller than a Lexus IS or Mercedes C-Class. But you can still add more cargo space by folding the back seat or seats, or employing the ski sack pass-through for longer items.

Avants (again, according to Audi's latest figures) have roughly 28 cubic feet of space behind the back seat and 50 cubic feet with the seats folded. A side pocket with cargo net, good floor-mounted tie-downs at the corners and a pair of pivoting rings at cover height that can be used as tie-down points or grocery-bag hooks add to its versatility. The cargo floor can be flipped over to a plastic well for carrying messy stuff, and a roll-up net separates cargo or animals from people.

When you open the hatch, which can be powered and set to stop at any height, the cargo cover can be released up and forward for better access or rolled up behind the seat. The load lifting height is lower than in the previous generation, and the hatch opening (39 inches at the base) is bigger.

Driving Impressions
The A4's 2.0-liter turbocharged four-cylinder is designed with everyday use in mind. It's not a fire-breathing hot rod like the turbo in a Mitsubishi Evolution, Subaru STi, or Porsche 911. With direct injection and variable exhaust valve lift, the Audi engine starts quickly and at idle has the faintest muffled ticking. Above that it's smoother because the turbocharger is spooled up and generating boost.

As a result, the 2.0T delivers 211 horsepower, 7 more than the Lexus IS 2.5-liter V6 and just slightly less than the 3.0-liter six-cylinders in the Mercedes C300 and BMW 328 (by 17 hp and 19 hp respectively). Yet far more important for the American driver in a 35 mph world is torque, and the A4's 2.0T dishes up 258 lb-ft of it. This diesel-like urge tops all of the aforementioned engines (by 73, 37 and 58 lb-ft respectively). So the A4 is more than capable of keeping up with or passing those other cars. The A4 2.0T can accelerate from 0 to 60 mph in 7 seconds or less.

More impressive is the width of the powerband, that area of engine speed that delivers maximum power. The 2.0 turbo makes big torque from just off idle at 1500 rpm all the way to 4200 rpm. And from 4300-6000 rpm it delivers the 211 horsepower. It will rev to 6700 rpm, but there isn't much point when you've got that much midrange power. None of the competitors has that kind of flexibility and, just to rub their noses in it, the A4 with quattro all-wheel drive betters the EPA fuel-economy ratings for the analogous BMW, Mercedes and Lexus by 1-5 mpg in both the City and Highway cycles. The A4 Avant 2.0T quattro is rated 21/27 mpg City/Highway. In our own mixed driving, which included elevation, rain and snow, it returned better than 25 mpg.

The continuously variable transmission in the front-drive 2.0T has wider ratios than in previous-generation models to improve acceleration and highway economy. In Drive it operates completely automatically. A CVT feels differently from a traditional automatic: Engine speed more closely matches how hard you're pushing the gas pedal rather than how fast the car is going, sort of like how a car with a manual transmission feels when the clutch is slipping (or a '48-63 Dynaflow, if you're old enough to remember Buick's gearless hydraulic transmission). With the lever in S for Sport mode the transmission makes eight steps automatically (to feel like gear changes even though they technically aren't). In Manual mode (+/- on the shift lever or shift paddles), you control those eight steps by moving the shift lever or paddles.

Six-speed manual cars have a precise shifter with good feel and movement. Likewise, the clutch pedal has simple, low-effort operation. A feature called the drive-off assistant keeps the brakes on while you transition your foot from brake to gas pedal, so even novices can manage an uphill start. Because the A4 can get heavy and the engine is only two liters you may need a few revs on for the smoothest takeoffs, a technique you'll learn by the third stop sign.

The six-speed automatic disengages when the car is in Drive but a foot is on the brake, to save fuel, wear, and the creep motion idling automatics want to do. The six-speed auto offers the same modes (D, S, and manual) as the CVT. In D it is smooth yet shifts quickly and maximizes mileage and comfort by using all the torque available. In S it delivers more response for the same gas-pedal application, doesn't shift under heavy cornering loads, and downshifts sooner; as in manual mode, downshifts are rev-matched for smoothness and longevity. In Manual mode you select the gear you want, ideal for winding elevation changes where you know what's coming and want to save a lot of shifting, in traffic to better control speed, or on long descents to save the brakes for stopping.

Most A4s come with quattro, Audi's all-wheel drive system. It makes acceleration easier and has differential locks for best low-speed traction. The default split sends 60 percent of engine output to the rear wheels for better driving dynamics and balance. The system is completely transparent to the driver and requires no action. All-wheel drive is more effective for acceleration than traction control because the latter achieves grip by reducing the accelerative force of the front tires. But remember that all-wheel drive merely provides accelerative force to propel the car, and to a lesser extent steer it in low-traction conditions. It does not repeal the laws of physics and uses the same tires and brakes to slow the car.

The A4's brakes deliver impressive slowing even on a wagon with a load on board. Outright stopping performance depends a great deal on tires so we're guessing the Sport package cars might stop the best. An electronic parking brake, operated by a switch on the center console, can give close to maximum effort when needed and hold a decent grade.

Weight and its distribution play a part in virtually every aspect of a car in motion. Most of the A4's suspension pieces are forged aluminum, as is the front crossmember; the anti-roll bars are hollow and the steering rack has been positioned for less weight in the moving parts. The rear suspension is sort of a small-scale A6 setup with toe-control trapezoidal links and separate spring and shock mounts that allow a lower floor but more suspension travel, a win-win situation. Also for better balance, Audi mounts the battery in the trunk.

More significantly, the longer wheelbase of the current model pays huge dividends in ride quality, stability, steering reaction, and braking. With the wheels farther apart and carrying closer to equal weight it's easier to make each do its own share of the work, so despite the nose-heaviness caused by the engine and driven front wheels the A4 feels lighter than it is and surprisingly adept at swallowing bumps and road imperfections while still delivering decent cornering. With quattro it's even better, and the wagon's extra weight over the rear wheels makes it entertaining.

Our first exposure to the A4 was in a base-model Avant 2.0T quattro Premium, meaning automatic transmission and generic tires. We were sent out on an active racetrack ahead of Mazda's sportiest RX-8 R3 and behind Audi's mid-engine R8 super-sports car running hot laps. The next six miles were laugh-out-loud fun as the R8 never got away and the RX-8 never caught up. In short, we were chasing an R8 in a station wagon. Of course, we're excellent drivers but it was plainly obvious the new A4 is a superb road car, one developed and tuned by people that commute at 130 mph.

Over a few hundred subsequent miles we found the A4 equally capable on any road. Longer wheelbase means more time between the bumps and everything gets smoother as wheelbase lengthens. But it never becomes soft or mushy and an impromptu speed bump test that began at 20 mph and progressed to 50 mph rode better the faster we went.

We really couldn't find any behavior the A4 does wrong. Yes, the electronic stability program intervenes on some roads because no stability system reads the road ahead, but it can be dialed back in increments to reward the smooth driver. On Sport suspension and tires the ride goes firm but never stiff, and the fun quotient goes even higher. At the highest level, the Drive Select system with dynamic steering and variable damping that calculates shock rates 1000 times/second gives the widest spectrum, from comfort-like a base car on 17-inch wheels to stick-like a Sport on 19-inch wheels, and you can program one mode to your liking.

We would advise caution considering 19-inch wheels for bad roads like you may encounter in the rust belt, or Arkansas I-40. They look great and stick well but cost a lot to replace when you bend or break them.

Outward visibility is good in all directions, aided by low-profile rear headrests, sensibly sized pillars, fog lights front and rear, and good wiper coverage (including the rear in the Avant, with dual washer jets). More expensive models also benefit from bi-Xenon headlamps that adjust aim at more than 75 mph, a backup camera with parking assist, and side assist for lane changes.

The A4 is also quiet to allow hours behind the wheel without fatigue. Despite the largish outside mirrors wind noise is hushed, road noise is kept to a minimum and the engine is heard only when you're working it.

The 265-horsepower, 3.2-liter V6 offered last year has been discontinued to make way for the return of the S4, now powered by a supercharged 3.0-liter V6 producing 333 horsepower and 325 pound-feet of torque. Like the turbo-four it's fueled by direct injection and breathes through four valves per cylinder; additionally the V6 employs a two-stage intake manifold for maximum flexibility. An optional active rear differential overdrives the outside rear tire in corners, forcing the front end to turn in more quickly. It also communicates with the vehicle's Drive Select system and stability control to help maintain control in emergency maneuvers.

With a six-speed manual transmission, the 2010 S4 rockets from 0-60 mph in just 4.9 seconds, which is quicker (by 0.4 seconds) than even the previous-generation manual-shift S4, which was powered by a naturally aspirated V8. And fuel efficiency is greatly improved, with the 2010 S4 achieving 18 mpg city/27 highway, compared to 13/20 for its immediate ancestor.

The S4 is also offered with Audi's seven-speed S Tronic automatic, wherein the top three gears are overdrives. The S Tronic uses dual input shafts and dual clutch packs to execute computer-controlled gear changes in just one-fifth of a second. Zero-to-60 time is exactly the same with the automatic, while highway fuel economy improves slightly, to 28 mpg. Both versions of the S4 are electronically limited to 155 mph.

Summary
The Audi A4 is a superb road car. The least-expensive model is nicely finished, has an interior hard to beat at the price and makes a very nice commuter without breaking the fuel bank; while the top-end versions are fitted out like executive autobahn missiles. This latest A4 has the goods to go up against its German competitors on the road and Japanese competitors on amenities and style. Arguably its four-cylinder engine is the best in the entry premium segment. Number-crunchers will find that more room, more power, better mileage, standard leather, and a lower price make a compelling argument.

G.R. Whale filed this report to NewCarTestDrive.com. John F. Katz reported on the S4.