2003 Audi RS6 vs Mercedes-Benz E55 AMG comparison

Meet the new Mercedes-Benz e55-AMG and Audi RS6, two storming V8 family vehicles that utilise forced induction to provide supercar performance in multi-door form.

You’ve gotta love the Germans, if only for being the world’s greatest drama-queens. From no other country could operas like those of Richard Wagner emerge – full of busty, deep-throated women wearing solid metal breastplates accompanied by the rolling thunder of tympani. From no other land could a heavy metal band like Rammstein surface, powering along on the industrial rhythms of a blast furnace while immolating their instruments, themselves, and, seemingly, the front three rows of the audience.

History records that the Germans see life as some sort of stage. Who can forget the greatest historical hits such as Attila the Hun’s sacking of Rome, the climactic and decisive arrival of the Prussians on the field at Waterloo, and the horror, the unspeakable horror, of the Holocaust. Generally, the Germans are prone to excess – both in the annals of history and in their automotive engineering. They imbue their cars with extreme performance, not out of the passion that drives the Italians, but because of their constant craving for high-calibre ballistics. Take the latest supercharged Mercedes E55-AMG and twin-turbo Audi RS6. These two over-achieving über-cars spawn naturally and spontaneously from an engineering culture that gave us battleships like the Bismarck, the first jet fighter planes, and tanks like the Tiger.

If they were both sedans, this pair would make a perfect comparison test to find the world’s most dynamic, yet family-friendly V8 sports-saloon. That our RS6 is the Avant version earns it the title of the highest-performing wagon on the market by default, albeit at a price pegged $5000 above the E55-AMG sedan. You’ll pay $230,000 for the privilege of driving the world’s fastest load-hauler, and $225,000 for the E55, arguably the world’s fastest sedan. Both ride the wings of forced induction to win these titles, with twin turbos and intercoolers distinguishing the RS6 from the ordinary S6, and a neatly installed supercharger marking the biggest difference between an E55-AMG and an E500 Avantgarde. But wait, there’s more for Mercedes buyers: another 500 cc of engine capacity gets chucked in for good measure, ensuring this car will be mentioned in hushed terms of reverence. It certainly makes HSV owners feel inadequately equipped when the E55-AMG pulls alongside at the lights, and their eyes are drawn immediately to the ‘V8 Kompressor’ side badges.

Inside both cars you’ll find all the equipment expected of the lofty price positioning: an airbag for every occasion, multi-zone climate control, power-adjustable leather seats, trim from a designer cocktail bar, hyper-intelligent ABS, etc., and while neither car’s a dog, they both have new tricks. The air-suspended Mercedes might consider its bellows springs to be the business, but for us, the Sensotronic brake-by-wire system is the best thing to emerge from Stuttgart since the first AMG-Mercedes. Over at Neckarsulm, Audi’s performance arm, quattro GmbH has been just as creative with the suspension of the RS6. By ensuring the shocks at the diagonal opposite ends of the car share the same oil reservoir, it’s been able to guarantee the oil will travel to the shock that is carrying the most load, firming up the damping of that shock at times of need. The result is amazing: a dramatic reduction in body roll, pitch, and squat, and shocks that are able to deliver both resilient damping during hard cornering, and exemplary ride quality in straight-line running.

The throttle is a trigger to ballistic performance in both cars, but comes with a different action for a similar reaction. The Merc’s may be accelerate-by-wire, but the long, slightly stiff travel does a good job of disguising the engine’s extra urge until you’re used to it. It’s only when you mash it all the way to the firewall with the stomp of a hobnail-booted Frankenstein that the E55’s monstrous performance makes itself known. Until that moment this could be the ordinary E500 you’re driving.

By comparison, the RS6 has a hair-trigger. Helped by quattro GmbH’s re-programming of the five-speed automatic gearbox, the twin turbos serving the 4.2 litre 40-valve V8 seem always to be on the case. There’s no lag as the turbos pump up the boost from basement engine speeds, creating a minor localised hurricane in the induction pumping, and ramming the fuel-air mixture into well-aerated combustion chambers. The access to torque feels more immediate in the Audi because it requires just a caress of throttle compared to the big drop-kick of the Mercedes. There’s less need to crack the whip.

Once you’ve initiated a small Gulf War under the bonnet, both cars snap your head back into the headrest with acceleration comparable to a Ferrari 360 Modena. The metallic whine of the supercharger combines with the lusty V8 bellow in the Mercedes as it lunges forward with the potency of God’s own chariot. It’s a rough diamond of an engine, this super-V8, its Indiana Jones character personified by a lumpier idle and slightly more vibration that in the creamier Audi. But, my word, it doesn’t half go! We achieved a 0-100 km/h time of 8.0 seconds flat. That’s not so fast, you say. Well it was with the ESP system off and the muscle-pumping engine spinning the tyres all the way to the legal limit! The E55-AMG reached the target speed sideways in second, while leaving two continuous, fishtailing lines of rear rubber on the test track.

With no other sedan tested so far so willing to leave its mark on the road, the E55 needs that ESP system like a high-wire circus performer needs a safety net. Re-activating it dropped the 0-100 performance into supercar territory, the E55 suddenly hooking up and driving forward like one of Tiger’s shots off the tee. The ESP-off button equally acts as lawsuit insurance for Mercedes-Benz. Those who push it take their destiny into their own hands, and enter a realm where sudden and savage, life-threatening oversteer needs quick reflexes and intuitive driving responses to overcome it. It’s the ESP system that makes the E55-AMG a litigation-free sports-saloon for Mercedes-Benz. Without it, there’d be no St George to fight the Skid Dragon, no electronic cavalry to rescue any driver finding the 354 kW/530 Nm rear-drive powertrain inhabits territory outside his skill envelope.

Four-wheel drive makes the RS6 a more benign beast mechanically. Despite the extra 30 Nm of torque boasted by the turbocharged car and the arrival of maximum grunt at a more accessible engine speed, the adaptive all-wheel drive ensures there’s twice the rubber to transmit it into forward motion. The extra traction easily overcomes a minor weight handicap and a slightly lower power peak to make certain that the RS6 is the acceleration equal of the E55. It’s also the more refined of the two powertrains, as it’s less prone to vibrate and has a refreshing lack of whistling from the turbos. There’s no extraneous noise to contaminate the glorious sound of the most responsive V8 engine on the market.

With 560 Nm of torque available at just 1950 rpm, coupled to a five-speed auto programmed for quicker shifts and a more urgent launch than that of the usual Audi software, the merest whiff of fossil fuel gets the RS6 Avant charging forward with more urgency than any other wagon around. Even the last twin-turbo wagon produced by quattro GmbH, the legendary RS4 Avant, pales in any performance comparison to this bigger-bodied, V8-powered successor. It’s the ultimate stealth bomber on the market. The S6 wagon body, tastefully lowered on 18” alloys, lulls the surrounding road furniture into a false sense of security. Little do they know they’re sharing the tarmac with such a white-hot wagon, capable, like the E55, of a top speed in excess of 270 km/h should the 250 km/h speed restrictor, umm, suddenly find itself disconnected. Both cars sport shift paddles should the driver want steering-wheel control of gear selection. Both shift up automatically in manual mode should the driver find the maximum engine speed in a slightly dangerous ‘car knows best’ scenario. When it happens on a short straight on a winding road, sometimes you enter the next bend carrying 10 km/h more speed than expected. And were the ESP systems resting at this point, the consequences could be embarrassing. It’s a situation that might only happen to a few drivers around the globe, but it’s the Audi that’ll cope better with it. Few cars boast the physical grip of the RS6 on the road, courtesy of the race-car-like settings quattro GmbH selected in terms of camber, toe and roll-bar stiffness. More than a degree of negative camber added to the front wheels ensures the RS6 turns in like no other four-wheel-drive wagon. Understeer lives in the RS6 chassis well beyond the fear threshold of any driver worthy of the term ‘sane’, and it often takes an ‘incident’ to find it. Such as a corner suddenly tightening up, or the pesky transmission software deeming an upshift is necessary at precisely the wrong moment.

At all other times the RS6 is a sublimely simple car to drive quickly, a cut-and-thrust point-to-point champion of the five-door world, if not the four-door universe as well. For it humbles the E55 when it comes to feats of corner-carvery. Not only does it generate more lateral-g force before pushing straight ahead, but the suspension also controls shifts of body weight better and is less prone to bump-steer. With the steering of these two Shermans on a par – i.e., above average in terms of weighting and consistency, but slightly slow and lacking in communication – it’s suspension that most defines the Audi as the better choice for New Zealand roads.

For the air suspension of the E55 tries too hard to be a jack-of-all-trades, and succeeds in being a master of none. It needs the Active Body Control system of the SL55 to equal the anally retentive body movement control of the Audi. Without ABC, the E55 is more prone to the effects of weight transfer. Braking in downhill corners places more stress on the front tyres than in the RS6, and they’re more prone to squeal in protest. Powering off the corner, the rear-end squat also unloads the front end, and with the ESP system ensuring hook-up, there’s also a tendency for the Mercedes to run wide. This excessive weight transfer wouldn’t be such an issue if it arose from a deliberate compromise aimed at improving ride quality, but the E55 fails on that score as well. There are three settings for the pneumatic suspenders that Mercedes should call ‘hard’, ‘harder’, and ‘hardest’ for descriptive purposes. The latter setting is a guaranteed cure for constipation, and a test of the security of new tooth fillings. It’ll launch you clear off the driver’s seat, and ricochet the car all over a bumpy road. For as you up the resistance of the E55’s suspension, you also increase the car’s tendency to bump-steer. Best reserve the harder settings for smooth race-tracks only. Then again, perhaps it’s better to forget that they’re there. The RS6, like any other quattro GmbH product, arrives with a firm ride, but there’s less initial resistance in the wheel travel than with the E55, despite the 19” wheels fitted, making it arguably the more comfortable vehicle. It’s also the quickest stopper of the pair. Although both earn a braking upgrade because of scorching powertrain performance, the DRC of the RS6 eliminates nose-dive during an emergency stop and maintains the braking power of the rear tyres, where the Merc would rather transfer most of its mass to its skinnier front tyres. Hence the slightly more arresting stop of the Audi at 35.52 metres from 100 km/h, compared with 36.79 metres in the Mercedes.

Design-wise, the extra frills and flourishes of the Mercedes will appeal to a different person than the simpler, Bauhaus-inspired form of the RS6. Both are good-looking cars, but if it were a beauty contest, I’d be giving the lower stance and more voluptuous wheel arches of the RS6 the sash. As for the gulping honeycomb-covered grilles, twin oval-shaped exhausts, and beefy alloys with spokes the size of broadswords – hubba, hubba. Inside, both cars cry out for a user-friendly control interface like the MMI system fitted to the coming new Audi A8 saloon. You face a plethora of controls in both, like you’re on the set of some submarine movie, and the Mercedes is even more complicated by the need to select suspension and ride-height settings. There’s a sportier ambience inside the RS6 thanks to its more legible tachometer (the Mercedes’ is harder to read than the clock), the extra lumbar support of the front seats, and a smaller-diameter steering wheel with a slimmer airbag than the fat-hubbed Mercedes item. There’s a proper handbrake as well, just in case a little brake-slide is in order. The Mercedes, like most products wearing the three-pointed star, scores a foot-operated parking brake instead.

Looked at purely in dynamic terms, the RS6 wins this comparison test. If it’s image you’re after, the E55-AMG delivers the message with more clarity that you’re driving the meanest son-of-a-supercar in the valley. Both vehicles walk tall and carry big sticks, but it’s the Mercedes that has Aussie V8 owners feeling most inadequate. The Audi they don’t really respect until it emphatically files them into its rear-view mirrors. Meanwhile, the German power war carries on in the sports-sedan sector. Further plans for world domination include forced-induction V12 and V10 sports-sedans from Mercedes-Benz-AMG and Audi-quattro GmbH. For now BMW is working hard on its 10-cylinder replacement for the mighty M5. In terms of four-door donner und blitzen (thunder and lightning), the storm has only just begun.