| Driving Impressions The Mercedes E-Class cars are really quiet. There's very little vibration anywhere in the cabin, and almost no wind noise. Even the high-performance E55 AMG is so quiet that the driver forgets just how powerful, quick and fast it is until full throttle is explored. Performance from the E320 is somewhat disappointing. Its 3.2-liter V6, which produces 221 horsepower and 232 pounds-feet of torque, lacks the responsiveness of the E500. However, the E320 cruises well at high speeds and the V6 is smooth and quiet from idle to the 6000-rpm redline. The E320 can accelerate from 0 to 60 mph in 7.1 seconds, according to Mercedes. The E500 is much more responsive than the E320. Most of this is due to its more powerful engine. The acceleration performance from the E500's V8 is truly impressive. Acceleration-producing torque matters more than horsepower numbers for most drivers, and in this class the E500 is hard to beat. You'll notice when you step on the gas. This V8 is nice and smooth from idle to the 6000-rpm redline. And the E500 flies. At a stoplight or from 70 mph, there's a deep well of torque underfoot, and plenty of acceleration. From the seat of the pants, the E500 feels like the quickest car going among mid-size luxury sedans. Mercedes engineers say it's even quicker than the 500E, a limited-production, purpose-built sports sedan developed with Porsche in the early 1990s and still revered by auto enthusiasts today. Mercedes sticks with its tried and true single-cam, three-valve technology for all of its E-Class cars, which may help explain slightly lower specific output than some competitors (horsepower per liter of displacement). The 5.0-liter engine in the E500 produces 302 horsepower at 5600 rpm, but, more important, it generates 339 pounds-feet of torque that's available from 2700 to 4250 rpm. Translation: quick response whenever you hit the gas. The E500 can accelerate from 0 to 60 mph in 5.8 seconds, according to Mercedes. Engine performance in the E55 AMG is truly impressive, with huge amounts of torque available from idle to over 5000 rpm, and peak torque over 500 foot-pounds. Its 469 horsepower comes partly from a Lysholm screw-type supercharger and intercooler plus the latest in ME 2.8 engine control electronics. No matter where or when you stab the throttle the E55 AMG just flat flies. Mercedes says it will go from 0 to 60 mph in 4.5 seconds and can reach an electronically controlled top speed of 155 mph in a little over half a minute. Yet, like the other E-Class engines, the supercharged V8 is always quiet and smooth from idle to the 6000-rpm redline. For 2004, E500 sedan and wagon benefit from a new seven-speed automatic, the world's first. It quickens acceleration performance and response yet enhances fuel efficiency when compared to the five-speed automatic, itself a responsive and efficient transmission. Gear changes are barely noticeable, especially in the higher gears. This new transmission allows significantly quicker acceleration for highway passing situations. And it doesn't have to go through every gear: Step on the gas and the transmission will skip down to the appropriate gear, switching from seventh to fifth, for example, and from there directly to third, two downshifts instead of four. The five-speed automatic transmission that comes in the E320 and E55 AMG shifts quickly up and down through the gears, though it sometimes seems slow to respond in the E320. It doesn't hunt back and forth for the right gear, even in hilly terrain, and it rarely shifts unless the driver changes the angle of the gas pedal, both of which are good. When the driver prefers, an auto-manual shift mechanism allows a high level of control over gear selection. Toggling the shifter left or right, the transmission shifts quickly up and down through the gears. The system will hold the selected gear indefinitely just below the 6000-rpm redline, but it won't let you bump the engine off its rev-limiter without shifting up a gear. The transmission controls will protect the engine by not allowing the driver to select too low a gear for a given road speed, but as soon as the car slows sufficiently, the transmission shifts down. Should the mood strike, a driver can run through the gears or challenge a curving stretch of road almost as if it was a fully manual transmission. The E-Class cars offer the cornering of a sports sedan along with smooth, though firm, ride comfort. The four-link front suspension is similar to that of the expensive S-Class sedans, and its five-link rear suspension does a superb job of controlling unwanted wheel movement, a key to good handling and ride. The E320 we drove had ordinary all-season blackwall tires on it, but the suspension works well with these tires and the owner can opt up for bigger tires and alloy wheels from Mercedes-Benz or from the aftermarket if a little more grip is desired. A new version of the air suspension from the S-Class, called Airmatic Dual Control, comes standard on the E500 and is available as an option on the E320 ($1,575), and replaces conventional steel coil springs with air springs. This computer-managed system adds more or less air pressure to the spring at each wheel, based on road conditions or driving style, to slightly soften or firm the ride and add or decrease body roll (the left or right lean when the car turns). In combination with electronically adjusted shock absorbers, the air suspension can automatically improve ride quality or handling characteristics, or optimize the balance of the two, depending on where the car is traveling and whether the driver is dawdling or going quickly. The system works automatically, without switching suspension settings between sport and comfort. The Mercedes E-Class has quick steering compared with other cars in this class. The variable power-steering system works well, with more boost for easy turning at low speeds, and less for more progressive steering response and feedback at higher speeds. The light steering makes maneuvering through crowded parking lots easier and more pleasant. Overall, this latest generation E320 is far more pleasant to drive than the old E320, which itself was a good car. The new E-Class cars feel agile, light on their feet. They respond more precisely, more like a BMW. The E55 AMG supersedan has a different suspension and different ABS and ESP settings in its software, deliberately changed to allow the driver to push the car to higher limits before electronic intervention takes place. The E-Class cars have excellent brakes from a performance and safety standpoint. At least one tester found them a difficult to modulate in everyday driving, however, making smooth braking around town a challenge. The E-Class features Sensotronic Brake Control, commonly called brake-by-wire. The connection between the brake pedal and reservoir of brake fluid is electronic, not mechanical or hydraulic. The advantage? The electronic system can apply brake force to each wheel independently, helping to keep the car traveling straight and true during panic stops, even on bumpy, uneven roads. It will also keep the brakes on full in an emergency situation, as measured by sensors, even if driver eases off the brake pedal, a common mistake. And if it's raining, the system periodically, lightly, applies the brakes to sweep them dry. Each of the three models has progressively larger brake rotors. The brakes on the E320 are excellent in terms of performance. With about 56 percent of its 3990 pounds on the nose and 44 percent of the weight on the rear tires, this car stops like a race car in street conditions, straight, true, and short, with no drama whatsoever, and will do so through a whole day of passionate driving. |