At the Paris Motor Show in September 1998, the public was introduced to six S-Class sedans in the W 220 series, which succeeded the W 140 series after seven and a half years. It was almost delicate by direct comparison, for somehow the designers succeeded in accommodating the same feeling of space and presence within a much more slender body. But unchanged was the same aspiration to set the trend for automotive design as a whole. On its debut the new S-Class displayed over 30 technical innovations, including the DISTRONIC autonomous intelligent cruise control, navigation system with integrated congestion warning and automatic cylinder shut-off in the V8 engine of the S 500. And later came the pioneering safety system PRE-SAFE.
When the Mercedes S-Class W 220 series was launched, there were initially two body and three engine variants. Mercedes customers were given a choice between the sedan with a short wheelbase (2965 millimeters) and the model with a wheelbase twelve centimeters longer (3085 millimeters). For each body there were three engines available. The S 320 had a 3.2 liter V6 engine 224 hp; the S 430 a V8 engine which delivered 279 hp; and the V8 in the top-of-the-range S 500 provided 306 hp. All three units offered optimum combustion thanks to their three-valve technology and dual ignition. Dual ignition also made it possible to increase the volume of exhaust gas fed back into the engine, with a consequent beneficial impact on emissions.
Automatic cylinder shut-off
The newly developed automatic cylinder shut-off turned the eight-cylinder S 500 temporarily into a four-cylinder - a feature which had a dramatic impact on fuel consumption without compromising on smoothness, torque or quietness. To put that into figures, when four of the eight cylinders were shut off under partial load conditions, NEDC fuel consumption (New European Driving Cycle) for the S 500 was cut by an average of seven percent. Indeed, thanks to the automatic cylinder shut-off even greater economies were to be achieved depending on driving circumstances: At a constant 74mph gasoline consumption fell by about 13 percent, and at a constant 55mph by as much as 15 percent. The automatic cylinder shut-off was activated whenever the V8 engine was obliged to deliver only a fraction of its output and torque - for example, in city traffic, on trunk roads or for steady motorway driving at moderate speed.
At the Geneva Motor Show in 1999, a new family member, the CL coupe, celebrated its world premiere. It featured for the first time as standard the innovative suspension system Active Body Control (ABC), which represented a hitherto unachieved optimum balance of sportiness and comfort. A system based on signals from sensors and using special hydraulic cylinders on the axles, ABC compensated almost entirely for any rolling and pitching motion of the body when moving off, cornering or braking. Two engines were available: The CL 600 had the twelve-cylinder unit with 367 hp, and the CL 500 the 306 hp V8 engine.
The S 600 was only available as a long-wheelbase version. The newly developed V12 engine was the same as the unit used in the CL. It was fitted as standard with such technical innovations as automatic cylinder shut-off, phased-control dual ignition, three-valve technology and AC ignition, and delivered 367 hp with maximum torque of 530 Newton meters at 4100/min. That took the S 600 from 0 to 60mph in 6.3 seconds and gave it an electronically limited top speed of 155 mph.
The S 320 CDI was powered by an advanced six-cylinder unit with direct diesel injection, VNT turbocharger and four-valve technology. It generated 197 hp and at 1800/min developed maximum torque of 346 lbs-ft. In the new European driving cycle the six-cylinder sedan used just eight liters of fuel for every 62 miles, giving it a range of almost 683 miles with a full tank (88 liters).
A bi-turbo diesel
The V8 engine with bi-turbo system in the Mercedes S 400 CDI marked a further milestone in the long history of Mercedes-Benz compression-ignition engines. From a displacement of 3,996 cubic centimeters the CDI eight-cylinder unit developed 238 hp of output at 4000/min. Maximum torque - an impressive 560 Newton meters - was available much earlier, at between 1800 and 2600/min. As for fuel consumption, the advanced diesel injection engine here proved far superior to comparable gasoline engines, with a value of just nine liters per 62 miles.
The W 220 series made advances in all areas of automotive design. As such, the W 220 series weighed over 661 lbs less than its predecessors with the same equipment options - one of the most important conditions for reducing fuel consumption and increasing agility. Thanks to lightweight design, exemplary aerodynamic efficiency (drag coefficient Cd = 0.27) and advanced V6 and V8 engines, the W 220-series vehicles saved somewhere between 12 and 17 percent on fuel, depending on the specific engine, over predecessor models.
Fall 2001 saw the market launch of the W 220-series Pullman variant, with a wheelbase one meter longer than that of the long version. The additional space benefited the rear passengers and allowed a vis-à-vis seating arrangement. The Pullman was available with either the 5.0-liter eight-cylinder engine 306 hp or the V12 unit (367 hp). The basis of the vehicle was a reinforced body shell and modified running gear.
Production of the W 220 series is scheduled to end in fall 2005 to make way for the W 221 series. As befits the Mercedes-Benz S-Class, this new series will continue to set new standards.