Road Test: Audi S4

By Feann Torr - 13/Apr/2006

As a good friend and colleague of mine once said "The S4's reputation precedes it," and you know what? Mr Tomlinson was right. This high tech sports car features Audi's evolving quattro four-wheel drive system, a small bodyshell and of course a stove-hot V8 engine shoe-horned into its cosy engine bay. Simply put, the S4 is Audi's answer to BMW's highly regarded M3.

It may be in a slightly different genre - a 4-door sedan opposed to BMW's 2-door coupe - but the idea is the same: the S4 is a relatively small luxury car with a relatively large engine, both of which combine rather nicely to create a dexterous and powerful sports car for the driver who doesn't want to schlep around town surrounded by cloth trim, cheap switchgear and illogical ergonomics.

In this test we'll be poking and prodding the current S4 model (internally known as the B7), which features the non FSI version of the 4.2-litre V8 that pumps out more than 250 kilowatts of power, or more than 340 horsepower. For $131,200, you get quite a bit of kit here, with comfort, safety and power systems that are almost without peer, and for many, the badge of a luxury Germany marque adorning front and rear makes the ultimate statement. 

But badge value counts for naught as far as this test is concerned - all we're interested in is how this bad boy from the Bavarian city of Ingolstatd performs on the road, and to a lesser extent whether or not BMW should be pushing forward the release of its new V8-powered M3 and M4 sports sedans.

Drive: 4.5/5

The S4 looks quite flashy in its bright yellow paintjob, though the overall look of the S4 is best described as subdued. Where something like the Evolution IX gets a massive spoiler, bonnet vents and an aero bodykit compared to its donor car, the S4 gets a very mild upgrade.

But it's what's under the skin that counts most in this case, and while only the purists will be able to pick the visual differences between the S4 and its lesser A4 cousins, the acoustics are a dead giveaway.

Powered by a 5-valve per cylinder V8 engine - outputting 253kW @ 7000rpm - the S4 makes such an evocative sound for an engine of its size. It emits a really hoary burble low in the rev range that builds into a decidedly angry, and singularly sonorous note. In a word - exquisite.

Before we get to the car's open road performance, I must make mention of the S4's inner city abilities. With it's 6-speed auto and ample torque, the S4 is able to cruise about slowly with ease, and without wanting to sound too artsy, I have to admit that it is a consummate performer in and around traffic. The variable ratio steering makes slower speed manoeuvering an effortless exercise in simplicity, while proximity sensors front and rear combine to make parking a doddle. 

In general it's a very easy car to drive, with a very personable nature. And because of its relatively small size, navigating traffic and tight spots never becomes a case of “will I fit?”. 

The only negative aspect to driving in built-up areas is that - because it features a sporty (read: tight) suspension setup, the car's body tends to jiggle over uneven surfaces, and won't soak up extrusions in the road like an A8 would.

For the more adventurous drivers, the S4 immediately obliges with childlike enthusiasm when put to task. The steering tightens up as your road speed increases, as though going through a minor metamorphosis, and it's entire driveline and chassis have been tailored to handle high cornering speeds while keeping the driver cocooned in sporty leather comfort. I must admit however, that it did take me a little while longer than most cars I've driven to work out how to wring every last drop of performance from the chassis, to find the car's groove as it were. 

When I first fired it through a few of my favourite corners, I did get that ‘wooden’ feeling that people sometimes complain about when captaining an Audi. In retrospect, and far from anything terminal, I think the main thing that held me back from pushing the car too quickly was its weight. Tipping the scales at 1705kg the S4 did feel a bit ponderous initially, but as time went by I learned to place my trust in the clever AWD system formulated by Audi's performance partner, quattro GmbH. 

Indeed, the S4 has no right to develop such velocities through a corner for something of this weight, but it can. And frequently does. The quattro AWD system is always there to make sure the power hits the ground effectively, endowing the S4 with supreme levels of traction.

Once I had adapted to the way the car handles, which was on the third day of the test, it was just me, Ellen DeGeneres, and the S4 travelling incredibly quickly. Ellen was involved because Audi was kind enough to include the most impressive TV tuner in our test car. 

Anyway, when you've built the confidence to push the car, it becomes a tremendously quick mode of transport. For example, even when it's leaning on the outside wheels (shod with sticky 235/40 R18s) through a fast corner, the inside wheels bearing less weight are still making themselves useful; the levels of grip on offer in the S4 - even in the soaking wet - are a formidable ally in the pursuit of pace.

When you're hands are on the tiller, the feedback from the road surface is adequate, and the burly S4 tucks its nose in quite nicely when you initially build up steering lock entering a corner. There’s no sense of oversteer per se, and when given a bootfull of throttle mid corner, most times it needs very little steering correction and is able to doggedly hold its line thanks to its clever quattro synapses and amicable weight distribution. 

Feedback through the steering wheel is not the best I've tested (it’s a bit light), but in general it’s very easy to extract high levels of performance once you've built a bit of confidence behind the wheel, and the engine has the kind of personality that conveys happiness only when nearing 7000rpm, always begging to go faster. Though it’s not as quick as an Evo round a corner, it’s not too far off the pace, and would be a corker of a drive on the race track, changing direction very smoothly for something so porky. Left to right handers, right to left handers, whatever chicanery you’re faced with the nimble short-wheel based car can handle it. It really bangs through flip-flops and S-bends with a sincere disregard for the laws of physics.

As mentioned earlier, pushing the S4 to its limits is initially no cake walk, and that's because it's limits are quite lofty; the adhesion it has to the road is amazing. Sure, it has a slightly stiff ride in the city, but round corners it's an almost perfect balance between spring stiffness and compression and rebound, with just a touch of give in the damping rates so that if you hit a bump mid-corner it won’t unduly affect the chassis.

There was certainly no squat or dive that I can report when throttling hard or braking hard either. When you accelerate through a corner it just feels flat and neutral. And the brakes too. Some cars, for mine, get a little wishy washy under hard brakes as the vehicle's weight shifts about, but not this puppy. It’s very nicely balanced when decelerating, and rightly so: it's equipped with a dual-circuit brake system, ABS, EBD, ESP and a tandem brake booster. Front and rear ventilated brake discs measure 345mm and 300mm respectively.

There's very little body roll to speak of too (always a good thing in a sports sedan) and flying through a corner at 8/10ths, your head remains fairly level, allowing you look directly towards the terminator - the farthest point of the corner you can see - without straining too hard, and the feisty German seems to just follow the vector that your eyes and brain are constantly mapping out. The seating position is very good (and highly flexible), while the heavily bolstered leather Recaro seats lock your torso comfortably in place during high-G maneouvres.

At times it’s almost like you needn’t think; the car is simply in tune with the slightest of inputs from the driver, reacting cooly and calmly to a given scenario despite the outside world flying by at speeds that human bodies just weren't designed to withstand. And therein lies a large part of the enjoyment derived from enthusiastic driving - risk.

That said, the Audi is chock full of the latest and greatest safety features, such as ESP and a bevy of airbags, ensuring that even if you do come unstuck - like the journalist who reviewed the car before me and proceeded to crash it - you'll get some of the best automotive protection money can buy. And that's eternally reassuring, I can tell you.

Point to point, the S4 is veritable rocket. When you dump a rev-happy 40-valve V8 into small bodyshell such as the A4, hook it up to a an AWD transmission, fit it with big fat tyres and well sorted suspension, the result is mind-numbingly good. It seems to hunker down and just suck through the corners, which is odd considering the lack of any blatant aero aids. 

Though I wasn’t a big fan of the tiptronic gear stick function, where pushing forward changes up a gear and vice versa, the steering-wheel mounted paddle shifters worked a treat, and of the half-dozen or so cars with these F1-inspired paddles I’ve tested, this is the first instance in which I’ve actually used the them for prolonged periods and felt rewarded, and not retarded. The 6-speed ZF gearbox, similar to the one we praised in the new Falcon, is a quick shifter and can think for itself too boot, which is always welcome when cruising in standard ‘D’ or drive mode.

The S4 doesn’t get the dual clutch DSG, but I really don’t think it needs it. The ZF gearbox does a very good job of getting the power to the axles and shifts are relatively rapid.

The power delivery is impressive for an auto, and it’s got surprisingly good levels of engine braking for something with a torque converter, which helps greatly when you're hard on the brakes and need a little extra deceleration. And conversely, when you sink the boot, it’s got nice levels of torque down low and a remarkably strong top end that enables it to pour on serious amounts of speed when you keep the revs high. The torque is not body-flattening stuff, but a solid 410Nm of twist combines well with 253kW to propel the S4 from standstill to 100km/h in 5.8 seconds. 

There were times when I felt that the S4 began to give me too much confidence as I laughed maniacally at the ploddingly slow cars I was passing in what would have been a yellow blur of Teutonic brilliance.Once nicely settled into the way it grips under full power, you can sometimes become a little  blasé about slamming the throttle into the plush carpets, and all of a sudden - cripes! - you’re in a four wheel slide. 

From inside the car, I now know why Damo (senior writer) likes his Audi’s so much. Everything's easy to read, easy to use, and nice to touch, and it's the small things make the driving experience just that little bit more enjoyable, which I'll get to in the 'Interior' sub section of this review in detail. 

All told, there's a lot to like about how the S4 drives. It's ability to grip the road and accelerate through corner entries, where many cars would need to ease off, and to then blast through the exit of a corner as the engine revs keep rising is astonishing. As some would say, it's the ducks nuts.

Engine: 4/5

When you start this puppy up and it begins to growl at you it’s perpetually pleasing, simply because one doesn’t expect to be witness to such a crisp-sounding bark emanating from such a small car.

Who would have thought that one day you'd be able to purchase an Audi A4 with a 250 cubic inch V8 engine - madness or genius? I'd have to go with the latter.

It’s got a very precisely engineered sounding thrum, and it's 5-valve per cylinder setup gives a wonderfully distinctive 'blat' when you floor the throttle. Evocative is an understatement.

And then there is the practical application of the 4.2-litre V8 engine - to propel the S4. Audi appears to have tuned this engine perfectly, because right across the rev range its a delight to use. Throttle response is perhaps a little too sensitive for my liking, but as with any car one can adapt. From low revs the engine delivers ample torque, where the mid range becomes and more insistent and then there's the smashing top end, which delivers power strongly and consistently much to the merriment of the driver.Just after 4000rpm is where the 5-valve V8 begins to makes itself presence unanimously felt, really kicking in the bass and upping the engine speed.

In addition to developing a very healthy power peak, the S4 does an immaculate job of ensuring every last kilowatt is slammed into the asphalt effectively, making use of Audi's quattro permanent 4WD system. This quattro system includes a Torsen (a.k.a torque sensing) AWD centre differential, which uses gearing rather than clutches to add or remove torque from individual wheels as torque requirements and traction conditions change. It's a traction manager of sorts, and a very classy one at that, not to mention expensive and very hard wearing. There's only one company in the world that produces these Torsen diffs (JTEKT Torsen, I believe), and few car builders beyond Europe's prestige marques use them in passenger cars due to their cost.

The ESP system combines with the quattro AWD to give the car an even greater roadholding ability, which can further control torque distribution and even brake individual wheels when the car's actual direction doesn't relate to the drivers intended trajectory.

Though I mentioned that the S4 employs a rather sensitive drive by wire throttle, it is quite easy to modulate. You can depress it a few degrees to get moving and as you give it a few more degrees you can feel the fuel injectors adjusting the output in measured amounts, as the engine speeds up incrementally, and this comes in handy during cornering; the ability to add and subtract acceleration in relatively precise amounts.

At freeway speeds you may be surprised to discover that it’s rather quiet car, with just a hint of tyre noise. The engine ticks over at 2000rpm when travelling at 100km/h in 6th gear in drive and I have to say, for such a blocky-looking sort of car, it’s interesting to note that there’s barely any wind noise.

And how’s this: when you pop the gearbox from its regular 'Drive' operating mode into sports mode the engine reverts to a 5-speed setup. Very cool. And it really works. Sports mode also ups the revs at any given road speed and is less likely to up shift to conserve fuel. From here you can use the gear lever or the paddle shifters to initiate the tip tronic mode, giving the driver even more control over the car's velocity.

The engine can be quite thirsty at times, but if you're willing to spend one hundred and thirty thousands bones on your ride, you probably won't mind too much. It'll drink 12.4 litres of fuel for every 100km travelled on the combined city/highway cycle, and will drink almost twain that amount when pushed.

Exterior: 4/5

Though the S4's appearance doesn't quite match it's performance abilities - kind of like a dwarven basketball champion - it's still an attractive vehicle.

Chrome is used strategically on the S4, and it looks great: the window line is finished with a thin chrome line, there’s touches on the rear end, and there’s plenty on the grille as well, while the silver wing mirrors up the shiny quotient and when taken as a whole these accents give the S4 a very classy appearance. It adds that special something that a massive rear wing could never replicate.

Visually the car has good proportions front to rear, though it does have a slightly longer front overhang than the lovely looking BMW 3 Series.

Subtle bodywork gives the S4 a quiet visual status, though driving through the city of Melbourne, the yellow coloured car did get some admiring stares. It also got some shocked stares as onlookers heard the engine. From within the cabin the sound is glorious, from outside it's even better.

Even with mild applications the deep wob wob piques interest like not even the M3 can manage with its tinny, raspy F1-like blare. It’s a performance sedan of magnanimous proportions covered up in an unambiguous shell, if you like.

It's not wildly dissimilar from its predecessor, save for the massive single-frame grille, modernistic headlights and taillights, yet emanates a tough Germanic style that brought a grin to my face every time I caught it's reflection in a shop window or glass-transport truck.

The wheels I’m no fan of. They're 18-inch Avus designed jobbies with fat enough rubber, but even-numbered spokes don’t do it for me when it comes to fancy wheels, and though the six-spoke design seen here is quite technical looking, it fails to excite the eyes when viewed at standstill.

Interior: 4.5/5

The first thing I noticed when I sat down in the S4 and had a quick look around was that it’s not the biggest of cars. But due the adaptable and very cushy Recaro seats and clever use of the space available, you tend to forget this after pulling away from the kerb.

Seat adjustments were located on outside edges of the seat bases (between the doors) and they were very comprehensive. There was lumbar, fore/aft, raise/lower - you name it About 10 adjustments all up. The front seats also had useful under-thigh pullouts that extended along the car’s length, which I found to be very useful, capping off the perfect seating position for a long slog of hard driving.

The front Recaro seats, finished in a very high quality leather, are some of the finest pews I’ve sat in, and would you believe the rear seats are Recaros too! The side bolsters of the sports seats are particularly reassuring and if you pull down the centre armrest in the rear, you’ll find a well stocked first-aid pack and a pair of cup holders, so you can drink savlon if you like. The car has a really good driving position too - it’s easy to get the all-encompassing view over the bonnet. 

There were a lot of features to take in when you step inside the car, including the dual zone climate control and one very busy-looking centre console, but thankfully the MMI (multi media interface) has been astutely programmed with a clever input device - a twist-and-click dial - and as a result navigating its myriad menus is pleasantly intuitive.

Having a TV option was interesting, and a first for the author. The signal is often a little average (and disappears completely in underground car parks), and the screen only comes on when the car has stopped, but the audio is constant. It’s a brilliant option in the stop-start peak hour traffic, and certainly surprised two police officers who pulled me over on a chilly night in down town Melbourne, asking why Dr. House was screening in the car. Allegedly I was going round a corner, and I quote, "On two wheels" which is hard to do at 50km/h. But they were clearly impressed with the car, proceeding to ditch their usual bravado in favour of enthusiastic curiosity. Gotta love the S4.

Auto up and down on all windows was a greatly appreciated, and generally speaking, I’ve sat in few cars that are altogether as ergonomically designed as this. All the switchgear is great; ergonomic, nice tactility and well placed. I can see why Damien always raves about the interiors of Audis. The plastics used are quite nice, dash plastics are likewise good quality, the leather steering wheel featuring audio controls (though could be a little sportier/smaller), the door trims feature leather with a bit of faux graphite and all the push-buttons feel really good and every just works.

Easy to read dials make avoiding the incredibly low tolerances on Victorian roads less problematic (just 3km/h over in a 100km/h limit or you're a bonafide criminal). The dials aren't super special - chrome rimmed, with the tacho on the left sporting an S4 logo. It works though, in a subdued way, in a similar vein to the exterior approach.

The centre armrest was the perfect height for my elbow to sit upon, and I should say that the sat Nav is very impressive too - one of the best systems I’ve had the opportunity to sample. It splits the visuals between the main MMI in the centre console and the smaller LCD central display, which is conveniently located between the speedo and the tacho right in front of you, and it's also got a thumping stereo with 10 speakers.

But there is one thing that soured it slightly (but wouldn’t be an issue Germany), and that is the handbrake placement. Audi should chuck an electronic push-button handbrake in there, as the right-hand drive models we get here have the handbrake lever tucked away to the left side of the centre arm rest, meaning you have to reach around awkwardly to pin down the car once parked. Furthermore, the indicators are the wrong side of the steering wheel for Australian drivers, as are the cruise control options. Great sounding doors though, emitting a satisfying 'whup' of sorts. 

Front and rear proximity parking sensors come in very handy, as this is one car you don’t want to inadvertently scratch. Or drive into a ditch. Boot space, meanwhile, is impressive. It's long and deep, with a 460 litre capacity (up to 833 litres with the rear seat folded down), but isn't particularly wide.

While the front seats are supremely comfortable and rather roomy, the rear seats aren't quite as generous, and the middle seat in the back is kind of useless. Because the car is only (1781mm) wide, the middle rear seat gets very little width, and trying to squeeze more than two adults in the rear is like trying get direct answer from a politician.

Overall: 4.5/5

Audi is definitely on to something with its S4. Combine a torque-laden, high tech V8 with the relatively small bodyshell of a ridiculously well-equipped A4, include a ream of sporty trimmings, inside and out, not to mention a rock solid AWD traction system and the result is hard to top for sensory pleasure.

I was never in doubt that the interior of the sporty Audi was going to be lacklustre, but as I said in the intro, badge value counts for naught if the vehicle doesn't inspire the driver. Thankfully though, the S4 is rather inspirational, and dynamically speaking it's hard to criticise. If you can afford the price of admission (and you're not downgrading from a Lamborghini Gallardo), you'll find there's a lot to like about how this car approaches different situations. The every day slog to work is made all the more relaxing thanks to the well insulated, ergonomic and luxurious interior, while the powertrain and chassis combine to give the vehicle the kind of at-the-limit resolve that would truly shock many drivers.

Exhibiting a very different approach to the way it corners, the AWD Audi would certainly give the rear wheel drive M3 a run for its money and, yes indeed, it could well be time for BMW to start making some noise about its new M3/M4, because this Audi is hard to fault. Not only is the interior incredibly sumptuous, yet suitably sporty, but the aural delights and physical power that the V8 bestows upon the stocky German is sublime. 

Buy it for the badge value, drive it for the thrill.