During a recent trip to Washington DC, I was handed the key to a glistening Verde Brook (think metallic dark brown) S63 AMG. After a quick walk-around, which required prying myself out of its cavernous second row (complete with opulent heated and cooled reclining seats equipped with marshmallow-soft pillows), I dropped behind its steering wheel, fired up the engine and pointed its nose south. My destination was 300 miles away, which should have taken just over four hours, except this was a summer weekend and I was heading down dreaded Interstate 95 with a few million other motorists.
- At the heart of the S63 AMG is Mercedes' twin-turbocharged 5.5-liter M157 V8 mated to a seven-speed MCT "Multi Clutch Technology" planetary automatic transmission, which sends power to the ground through the automaker's rear-biased 4Matic all-wheel drive system. Although down on displacement compared to the S600 and with less output than the flagship S65 AMG, the S63's quicker gearbox, lighter chassis and the ability to distribute the power to all corners gives it the edge in acceleration.
- A suite of AMG upgrades, which adds a breathtaking $45,100 to the price of a standard S550 sedan, includes more than just a robust powertrain. In terms of performance, the Airmatic air suspension is retuned, the brakes are upgraded to provide more stopping power and shed heat more effectively and the exhaust is opened to improve breathing. The operator is able to adjust the chassis tuning with a two-mode (Comfort and Sport) button and control the powertrain response with a three-mode button (Comfort, Sport and Manual) on the center console.
- The view from behind the wheel offers a few subtle hints of this AMG's potential. The digital primary instrument cluster is emblazoned with "AMG" script, the center armrest features an embossed AMG logo and the steering wheel ditches wood in favor of dimpled leather and paddle shifters. Although the Active Multicontour AMG seats have more aggressive bolstering, they lose nothing in the category of comfort – call a chiropractor if you don't consider them absolutely blissful.
- Unlike its boastful C-Class and E-Class AMG siblings, which announce their muscle with a throaty roar, the S63 is eerily quiet from inside the passenger cabin. Those with attentive ears will note a distant rumble when the throttle is prodded, like thunder from a storm 10 miles away. Even when the accelerator is mashed into the thick carpet and occupants are pressed firmly into their seats, the exhaust note from the AMG-signature quad pipes will not drown out normal conversation.
- The S63 AMG covers ground effortlessly, with the digital needle of the tachometer barely moving above its idle position at low I-95 speeds. Traffic congestion is dismissed by the excellent Distronic Plus adaptive cruise control with Steering Assist, a system that does everything short of eliminating the human operator. Even so, the S63 remains engaging to drive when the driver wishes it to be so – the steering provides more feedback than the S550, which could be attributed to the standard 20-inch wheels and performance rubber.
- Driving the S63 AMG gives the driver a well-deserved superiority complex. The odds of meeting another machine of similar physical size, with equal or greater capability, are extremely low – it's the dominant lion in a giant nature preserve. In a week's time, I never crossed paths with another sedan that was quicker.
- Don't expect the AMG MCT-based powertrain to be as buttery smooth as the traditional torque converter-based powertrain beneath the S550, as the multi-clutch gearbox is juggling 664 pound-feet of torque. The tradeoff allows jaw-dropping acceleration with insanely quick shifts, almost bordering on brutal. Mercedes says it hits 60 mph in 3.9 seconds, but it actually feels quicker.
- The EPA has certified the S63 AMG with a fuel economy rating of 15 miles per gallon city and 23 mpg highway. Resetting the trip odometer before my six-hour trip returned 21.6 mpg overall at the end of the day. While it didn't match the Monroney, breaking into the low 20's with a 577-horsepower vehicle is reason to applaud. Of course, driving around town with a heavy foot is about half as efficient, but a 21.1-gallon fuel tank reduces the frequency of fill-ups.
- If granted three wishes with an eye towards improving the S63 AMG, I'd first make the trunk a bit larger. With just 16.3 cubic feet of capacity, it barely holds four standard suitcases (which doesn't leave any room for carry-ons). Second, I'd rewrite the programming code for the MCT gearbox, as low-speed drivability in Comfort mode needs polishing – my sensitive derriere could feel the clutches doing their magic in a slightly herky-jerky fashion, especially from 5 mph to 0 mph and back. Lastly, I'd open up the exhaust just a little bit more (how about a sport exhaust button?), as a vocal reminder of the range-topping capability hidden within its gorgeous bodywork - this fabulous machine deserves to roar.