Big Displacement, Big Love
Inside M-B's latest big-bore powerplant
As a replacement for AMG's much-loved supercharged V8, the new normally aspirated 6.2-liter V8 has big shoes to fill. No problem. AMG's powertrain wizards dipped into the firm's deep well of experience in racing and developed a wonderfully powerful successor. There was one problem, however. Mercedes wanted to fit its new seven-speed transmission in the car, but it couldn't handle the 516 lb-ft of maximum torque that was generated by the outgoing V8. The answer was to build a motor with less torque but with more displacement, more horsepower, and a loftier rev range.
The 6.2L is the first all-new production engine coming from the AMG workshops in three decades. Basic architecture is an all-new alloy block with a unique bore/stroke ratio and a fully boxed lower section to reduce crank movement; four-valve cylinder heads with vertical intake and exhaust ports for better airflow; specially treated ceramic-metallic-coated cylinders (said to be twice as hard as conventional cast-iron liners) to eliminate the need for bore liners; variable camshafts; and a magnesium two-stage variable intake manifold. Racing experience brought in bucket tappets to pop the valves, which lends the valvetrain the stiffness it needs for the higher rev range; vibration-cheating conical exhaust valve springs; and two large 70mm throttle bodies.
Smaller, lighter and cleaner running than the supercharged V8, the 6.2 is also being fitted, at least initially, to the CLK63, CLS63, ML63 and R63. We're also told it will fit quite nicely in the C-Class cars. For those who'd still like to buy a supercharged Mercedes, the blown 5.5L will continue for this year in the SL55 AMG and G55 AMG. All other AMG models are due to get the fabulous new 6.2L.-G.N.B.
2007 Mercedes-Benz E63 Amg
Layout
Longitudinal front engine, rear-wheel drive
Engine
6.2-liter V8, dohc, four valves per cylinder
Transmission
Seven-speed automatic with AMG Speedshift
Suspension
F: Independent four-link with double wishbones, gas shocks, stabilizer bar
R: Independent five-link, gas shocks, stabilizer bar
Brakes
Dual-circuit system, ventilated and perforated rotors, ABS, Brake Assist
Dimensions
Length x Width x Height (in.):190.3 x 71.7 x 58.4
Wheelbase: 112.4 in.
Curb Weight: 4,035 lb
Performance
Peak Power: 507 bhp @ 6800 rpm
Peak Torque: 465 lb-ft @ 5200 rpm
0-60 mph: 4.3 sec.
Top Speed: 155 mph (limited)
Why We Love It:
Limousine-quality ride, exceptional fit and finish, sports car acceleration
Why We Don't:
Less torque than the outgoing supercharged 5.5L... but we'll get over it
The Price Tag:
$83,000 (est.)