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From YourSITE.com Reviews & Road Tests My foot is planted on the right pedal as the serpentine ribbon of road descending out of the Angeles National Forest gradually becomes straighter and less steep. I complete the upshift to fourth gear, and then back off the throttle a bit. I haven’t looked at the speedo yet; my eyes have been scanning as far down the road as I can see, and now I’m hoping desperately that the oncoming car is not a California Highway Patrolman. The speed limit on this particular stretch is 55 miles per hour, and I must be doing at least 85. Convinced that the car ahead poses no threat to my driver’s license, I brave a glance at the instrument cluster to discover I’m doing more than twice the speed limit. Damn, this thing builds speed deceptively fast!
I’m in Audi’s all-new RS 4 sedan, built by the company’s in-house tuner shop, quattro GmbH and the pinnacle of performance in the venerable A4 line. At my beck and call are 420 naturally aspirated, high-revving horses. Weighing in at just under two tons, my stealthy, understated Avus Silver four-door comes to the table with a power-to-weight ratio of just 9.4 pounds per pony, putting it squarely in the territory once reserved for exotic cars with ridiculous silhouettes and questionable aerodynamic appendages. It will get to 60 from a dead stop in 4.8 seconds, but its lightweight V8 loves to run, and super-legal speed arrives much faster than you expect. Unlike the original B5 S4, and likewise the original RS 4 uber-wagon that never graced our shores, the new RS 4 forgoes turbocharging and relies instead on revs to make its power. The twin-turbo V6s in those cars were characterized by a raging torque swell from very low engine speeds that tapered off as it approached 6000 rpm. In sharp contrast, this new engine comes alive at around 3500 rpm and pulls effortlessly to above 8000. Elastic is the only word to describe the power delivery- it simply keeps making power any time you demand it within that broad sweet spot. The 4.2-liter V8 is based on the same compact engine that powers many other Audis, including the RS 4’s close relative, the S4. Internal differences, such as unique pistons, connecting rods, cylinder heads, crankshaft and main bearings, allow for greater efficiency and the ability to turn at much higher speeds. At redline the pistons are traveling at a racecar-like 25 meters per second. Like the now-retired R8 racecar, this high-performance motor utilizes FSI direct-injection technology, making it possible to run a 12.5:1 compression ratio. Peak power (420 hp) is delivered at 7800 rpm; torque maxes out at 5500 rpm with 317 lb-ft, but at least 90% of that is on tap between 2250 and 7600 rpm.
The engine is no doubt the heart and soul of the RS 4, but putting that power on the tarmac is the role of the quattro drivetrain. Only one transmission connects the V8 to the torque-sensing center differential, and it’s a close-ratio 6-speed manual. Specially geared for the powerband of the RS 4, it is blessed with short throws and a fairly precise action, though on more than one occasion I rushed the shift to third and found myself in no-man’s land. The clutch is firm but surprisingly light for the amount of potential it manages, and because of the more progressive torque and power delivery it will likely suffer far less abuse than its turbo-powered forebears. The raw kinetic energy is disbursed among the four wheels, but not equally. In a break from quattro tradition, the majority of the torque (60% of it) is sent to the rear wheels under normal conditions for a more dynamic and engaging driving experience (read: more like a rear-drive BMW). Should conditions demand it, however, all of the torque can be directed to either the front or the rear.
Massive 255/35 ultra-performance tires (either Pirelli P-Zeros or Michelin Pilot Sports) are mounted on lightweight 19-inch alloy wheels measuring nine inches wide at each corner. Optional in Europe where 18-inch wheels are standard, the American RS 4’s standard 19-inchers are surprisingly light at just 24 pounds each. Beneath them lies a serious set of brakes. Up front, 8-piston calipers grip 14.4-inch cross-drilled and vented composite rotors. The two-piece rotors are comprised of aluminum “hats” and cast-iron discs; this not only reduces weight but also the chance that the rotor will warp under severe duty. NACA-style ducts also help in this regard by delivering cool air directly to the brakes. In the back, single-piston calipers work on 12.8-inch discs, also composite, cross-drilled and vented. It’s not enough to simply talk about the hardware on a modern performance car. Electronic aids are just as important to the driving experience and overall performance potential. Given Audi’s reputation for advancing technology, the RS 4 is naturally well endowed in the software department too. Anti-lock brakes are standard fare these days, but the system on this car also features Electronic Brake pressure Distribution (EBD) and automatic brake disc wiping in wet conditions. The Electronic Stability Program (ESP) is there to watch over foolish decisions. It can be dialed down, removing only the traction control, but can also be completely defeated at two presses of the button.
At Willow Springs, I get my chance to see how all this sophisticated hardware really works. The nine-turn, 2.5 mile course is legendary for its challenging elevation changes and long straights that allow for incredibly high speeds. It turns out to be the ideal setting for putting the RS 4 through its paces. Within the first lap on the track, the RS 4 demonstrates its athleticism. It sprints out of the paddock and charges for the first corner like an NFL wide receiver. The combination of sweeping corners (2, 3 and 4) that climb into the base of the desert mountainside poses no menace to the Audi; the car simply handles them like a champ. Corner 5, downhill and hard on the brakes before a clipping the apex on the left, proves only a challenge to my nerves as the RS 4 is unaffected by it. It’s back on the throttle and up to fourth gear after 5. Corners 6 and 7 are not really corners at all, and the Audi is well into the double digits as the brakes get a light tap before turning right into 8 and sweeping into 9. Corner 9 terminates on the half-mile straight-away, where my RS 4 reached more than 125 mph in advance of a momentous braking session. It’s hot out here in the desert, and the temperature on the track is more than 100º F. Successive laps are making the tires greasy. Nevertheless, the car manages to cling to the track. At no time do the brakes feel overworked or show any signs of fading, despite the fact that my growing confidence has me diving deeper into every corner with each passing lap.
Before my lapping session ends, I remind myself to explore the “S-mode,” a sort of alter-ego program that modifies the engine’s personality slightly. At the press of the button, the ECU mapping changes, immediately delivering a sharper, faster throttle response. The intake and exhaust notes also become more aggressive and pronounced in this mode. Regrettably, I forget to try out the lap timer function built into the information display. I leave Willow Springs satisfied with the on-track workout. The RS 4 was nearly faultless. If anything, the car is so balanced, its limits are so high and its capabilities so broad that I’m convinced the car itself can make even a mediocre driver feel like Michael Schumacher. Those seeking a true challenge may prefer a car that is a little woollier around the edges. Conversely, there is a certain satisfaction in knowing you will probably be driving your RS 4 home from a day of track driving.
Returning to public roads for a side excursion up to scenic Mulholland Drive, I’m able to finally concentrate on the rest of the RS 4’s finer points. Its mechanical package may be honed for rigors of the track, but make no mistake, this is one refined road car. One look around the cabin confirms this. Comfort features abound in the RS 4, from power windows all-round standard for the USA, power locks and mirrors to automatic climate control and Nappa leather seating. Even with the extra luxury equipment added for North American specification, it’s obvious Audi spent a lot of time removing weight to keep the car as light and balanced as possible. The aluminum pedals and carbon fiber dash trim serve as symbolic reminders of this principle, but the real benefits are hidden beneath the paint. Both front fenders and the hood are crafted from aluminum, not only reducing overall weight, but also shifting the balance of weight away from the nose. It is for this reason the battery has also been relocated to the trunk. The standard sunroof can also be optionally deleted for greater weight savings. One area where Audi was unable to save weight was the front seats. The European RS 4 gets an optional set of special lightweight Recaros with full manual adjustment. Unfortunately, these seats are not equipped with side airbags, and they were also not designed with the passenger’s side occupant sensor now required for US sale. Instead, our RS 4 gets the European standard offering of 12-way power Recaro sport seats, complete with electric lumbar adjustment and adjustable thigh extensions. As nice as these seats are, they weigh in a full 30 pounds heaver (each!) than their European counterparts. I pull off to the side of Mulholland to snap some pictures before the sun goes down. From where I’m standing, the RS 4 is less about actual weight and more about gravitas. In a way that only Audi can pull off, the car looks like a bodybuilder in an Armani suit. It accurately and distinctly conveys its muscularity without ripping off its shirt and flexing its muscles in a gratuitous display of testosterone.
Credit goes to Audi’s designers for subtly sharpening the A4’s shape, forgoing tacked on visual drama. Indeed, the RS 4 shares only the roof panel and front doors with any other A4 or S4. Both front and rear fenders bulge slightly, but effectively, allowing for an additional 1.4 inches of wheel track. The trunk lid is enhanced by an integrated spoiler. The effect is so subtle that most casual by-passers will not bat an eye at the R S4, and that can be a good thing in certain situations. As with the interior, the RS 4’s exterior receives some unique visual treatments. The mirror housings, for instance, are shaped more aggressively than standard A4/S4 mirrors. They’re also dressed in a matte aluminum finish that coordinates with window trim and once again drives home the lightweight theme.
My time in Audi’s RS 4 is over too soon. Nevertheless, it is an opportunity few will experience. These will be exclusive cars, no doubt, as Audi North America only plans to bring 1000 or so examples here per year. Starting at $66,000, it certainly won’t be within everyone’s reach either. Considering what’s available for around 70 grand (as most RS 4s will likely list for) it makes a strong case for itself. It has the performance to match most dedicated sports cars, yet is fully capable of carting the family around town in comfort. Forget those swoopy things from Italy, the RS 4 is the true supercar. 2007 Audi RS 4 Base Price: $66,000 Delivery: $720 Options: Premium Package- $4700, Special Order Paint- $750, Rear Side Airbags- $350, Gas Guzzler Tax- $2100, Delete Sunroof- N/C, Aluminum Beltline Trim-N/C Technical Specifications Engine Type: 90º V8, all-aluminum construction, 4 valves per cylinder, FSI direct fuel injection Power: 420 hp @ 7800 rpm Torque: 317 lb-ft @ 6000 rpm Displacement: 4163 cc Bore: 84.5 mm Stroke: 92.8 mm Compression Ratio: 12.5:1 Redline: 8250 rpm Drivetrain Type: quattro all-wheel-drive, TORSEN center differential, electronically-lockingh front and rear differentials Transmission: 6-speed manual Transmission Ratios: 1st: 3.667:1 2nd: 2.221:1 3rd: 1.520:1 4th: 1.133:1 5th: 0.919:1 6th: 0.778:1 Final Drive: 4.111:1 Body/Chassis Body Type: Unitized steel shell with integrated magnesium and aluminum components; aluminum hood and front fenders Front Suspension: Independent 4-link, coil springs, gas shocks, anti-roll bar Rear Suspension: Double-wshbone, coil-springs, gas shocks, anti-roll bar Braking System: 4-wheel disc, anit-lock, rear-wheel mechanical emergency brake Front Brakes: 14.4-in rotors, cross-drilled and vented, composite construction; 8-piston calipers Rear Brakes: 12.8-in rotors, cross-drilled and vented, composite construction; single-piston calipers Steering Type: Rack and pinion, power assisted Steering Ratio: 13.1:1 Turns lock-to-lock: 2.5 Turning Circle: 36.4 Wheels: 9x19 Light Alloy, 29mm offset Tires: 255/35ZR19 General Wheelbase: 104.3 in Length: 180.7 in Width: 71.5 in (76.1 w/mirrors) Height: 55.7 in Track (F/R): 61.4 in/61.4 in Weight: 3957 lb Fuel Capacity/Type: 16.6 gal (US)/ 91 octane Premium Unleaded Gasoline Fuel Economy (EPA City/Highway): 14/20 mpg
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