Right car, wrong timing?
At a glance, it would seem that a high-powered German sedan is the wrong car for the times. The new arrives in the midst of a global economic slump. It was unveiled at the Paris show, where hybrids and electric vehicles stole the limelight, and it unashamedly advertises the brand motto Vorsprung durch Technik when everybody is talking CO2 and mpg and $$.
Look closer, though, and the new S4 emerges as a surprisingly sensible proposition. It costs less than the car it replaces, it’s 27 percent more frugal in the combined European Union cycle, and in format and appearance it is still perfectly socially acceptable both in sedan and wagon form. The truth is, the fastest version of the new A4 offers the best of two worlds. It’s an instant-torque fuel-miser that will return 39 mpg in extra-urban mode (on the European test cycle) to reward pussy-footed drivers. At the same time, it doubles up as high-tech tearaway that employs trick steering, chassis, and differential to beam you quicker from point A to point B than most of its rivals.
But who exactly are these rivals? At BMW, the 333-hp S4 splits the 306-hp 335i and the 420-hp M3. At Mercedes, it aims at the gap between the 272-hp C350 and the 457-hp C63AMG. The car has not yet been priced for the United States, but in Germany the S4 is about ten percent more expensive than the 335ix and about five percent dearer than the C350 4Matic. But in both cases, the Audi has a power, torque, and performance advantage over the competition. Late next year, we expect to see the new RS4/RS5, which is rated at 450 hp and 331 lb-ft of torque, sources claim. For the top-of-the-line version, the Quattro division will stick to the high-revving, direct-injection 4.2-liter V-8. It is in this context worth noting that BMW and Mercedes plan to embark on a different strategy. While the next M3 will switch from a normally aspirated V-8 to a twin-turbo in-line six, the C63 replacement is expected to shed its normally aspirated V-8 for a twin-turbo eight-ender with a displacement of only 4.6 liters.
Subtlety, thy name is S4
Our test car is bright red, but apart from the eye-catching color, it looks unexpectedly understated. The basic eighteen-inch wheels shod with 245/40 Bridgestone RE050A Potenzas are dwarfed by the wheelhouses that can accommodate twenty-inchers. The cosmetic changes aren’t exactly earth-shattering, either: alloy-capped door mirrors, the usual S-line trim bits, a slightly different grille pattern, metal horizontal diffusers front and rear, and that’s it.
No V-8? Isn’t that blasphemy?
A comparison of the basic engine data of the old and the new S4 does not bode well for the 2009 model: only six cylinders instead of eight, 3.0 liters of displacement instead of 4.2, 333 instead of 344 hp. Are we getting shortchanged here? We are not. The maximum torque, that crucial parameter for grunt and driveability, increases from 302 to 325 lb-ft. Better still, it is now available between 2900 and 5300 rpm rather than peaking at 3500 rpm. Audi claims that, although the curb weight has only gone down by about twenty pounds, to 3638 pounds, the new 333-hp S4 outsprints the car it replaces from 0 to 62 mph by half a second, with a 5.1-second run against 5.6 seconds. That’s the good news, part one. The bad news concerns the fact that when fitted with the desirable seven-speed dual-clutch S-tronic transmission, the four-door Audi needs an extra 0.2 second for the acceleration job, because the transmission makes an extra upshift. Now, let’s look at the good news, part two. Despite the better performance, the average combined fuel consumption has dropped significantly, from 17 mpg to 24 mpg.
Like all S and RS model Audis, the new S4 is deceptively fast. Its engine note won’t crack open birds eggs in the nest high above the tarmac when it hits the 7000-rpm redline, its chassis won’t out-meow the applauding cats that line the road as the car carves through a corner at full song, and its body language at the limit of adhesion won’t scare away the grazing cows. In this A4 on steroids, speed is barely audible, barely visible, barely decipherable.
While most engines saddled with a mechanical supercharger develop their sweet spot between 3500 and 5000 rpm, the 3.0 TFSI unit has fireworks all the way to its 7000-rpm cut-out speed. It thus combines the low-end torque boost of an artificially aspirated engine with the explosive, top-end energy of a high-revving, normally aspirated engine. The new V-6’s Roots supercharger produces oomph by the bagful at the word Go! That’s why the S4 takes off as if launched by a catapult, that’s why it responds to throttle inputs like a solenoid to an electric impulse, that’s why it has enough in-gear power to beam this five-seater from 50 to 75 mph in only 4.4 seconds in fourth gear.
Finally, the seven-speed S-tronic arrives in America
The seven-speed dual-clutch S-tronic, which makes its American debut here, definitely is the gearbox to go for. It offers two automatic modes (drive and sport), and it invites you to change ratios with paddles mounted to the steering wheel. The S-tronic is not only more relaxed and more efficient, it also is even more inituitive than the slick shifter and the fuss-free clutch.
The main advantage of the twin-clutch arrangement is of course the totally seamless torque delivery, which keeps up the momentum even during gear changes. In auto mode, the system can be outfoxed by certain borderline situations like aborted overtaking maneuvers or a sudden shift of driving style between open road and city, but the chips learn fast and the fluent functionalities of these wizard cogworks never cease to amaze.
Naturally, four-wheel drive is standard
Quattro is standard on the S4, and so is the 40:60 front to rear torque split. But to get the best out of four-wheel drive, you should specify the optional sport differential. Similar in function to BMW‘s automatic performance control device available on the X5 and the X6, the trick diff distributes torque between the rear wheels in a progressively variable fashion. Unlike the BMW concept, the Audi hardware also works under trailing throttle and even when the gearbox is in neutral. As the vehicle turns in, the sport diff automatically diverts most of the propulsion forces to the outer rear wheel. This reduces understeer, allows you to work with a more moderate steering angle, and improves the roadholding as well as the directional stabilty. At the limit of adhesion, when the rear ends begs to be reined in by the ESP, the extra set of cogworks keeps the tail in line by feeding twist action to the wheel that is closest to the apex. The response time of less than 100 milliseconds even beats the ESP black box by a small margin. The maximum torque difference between the rear wheels is substantial, but the biggest advantage of the sport differential is that instead of eliminating excess energy, it cleverly and smoothly redistributes it.
Audi Drive Select: fancy name for fancy dynamics
To specify the sport diff, you must first opt for Audi Drive Select. And if you’re doing that, you might as well also go for the extra-cost adjustable dampers and for the so-called Dynamic Steering. Drive Select offers an easily accessible personal choice of three different tuning stages, labeled comfort, normal, and dynamic. Via the MMI controller, you can dial in the preferred calibration of engine (throttle response), automatic transmission (shift pattern), dampers, steering, and sport differential. In a car like the S4, dynamic provides a nice mix of sharpness and balance, of tactility and feedback, of intuition and agility. It’s still possible to deactivate ASR and then ASR plus ESP, but this move doesn’t yield much anymore, because the north-south and east-west torque flow is managed to perfection by a couple of gear sets and their electronic brains. As a result, hard cornering is no longer a mix of more or less understeer. Instead, the nose turns in, the rear end tracks to match, and the ensuing four-wheel drift is easily modulated by throttle and steering in much smaller nuances than before.
If you love the way a 335i tackles a bend-rodeo-style sideways-then the S4 might bore you. But when someone poises the stopwatch and cordons off a given stretch of twisty blacktop, the fuss-free and focused Audi might well be quicker than the hooliganesque BMW. I’m of course biased, because I stepped out of my personal A5 coupe, which has Drive Select, Dynamic Steering, and all that. I like the steering to be light and quick at parking speeds, and I prefer it meaty and virtually unassisted on the autobahn. I also appreciate this momentary softness in the helm that indicates that the front wheels are about to run out of grip, when all it takes to bring life back into them is a little tug toward the apex.
The electronic damper control fitted to the S4 is not magnetic ride but a conventional system that varies the diameter of a valve to control the oil flow. More important than the switchable shocks are the changes made to the base suspension. To reduce the unsprung weight, Audi replaced certain chassis elements made of steel with new ones made of light aluminum. To reduce unwanted body movements, they fitted tauter springs and dampers, and they lowered the ride height by nearly an inch. To cushion excessive elastokinematic liberties, they installed stiffer mounting points. This setup works well, but I would not hesistate to opt for bigger nineteen- or twenty-inch tires. While they compromise the ride, they stick like superglue, and they make provision for the bigger seventeen-inch brakes, which are essential when hard driving is on the agenda.
A typically understated Audi interiorInside, the S4 is an A4 in monochromatic livery-black in the case of the test car. It sports redesigned instruments with gray faces, a special leather-wrapped steering wheel, comfortable and supportive motorized sports seats, a new type of high-tech mesh wire trim, and bespoke striker plates. Inside and out, the new S4 is an undercover fast-lane warrior rather than a baby RS4.
Yes, we like it
Audi has created a product that epitomizes sublime efficiency. It is introverted in appearance and delivery but extroverted in character and ability. Call it pragmatic, if you wish. Call it multi-talented, because that’s what it is. Call it the reincarnation of the Q-car. All it takes to enjoy it is to adjust to the S4’s minimum-input, maximum-effect approach. And to keep pestering the manufacturer for a more tuneful engine and exhaust melody.