The Mercedes-Benz relationship with its performance partner, AMG, is a classic Jekyll-and-Hyde, good-cop/bad-cop situation. Whereas Mercedes-Benz has to demonstrate a fair bit of corporate responsibility, AMG is pretty much free to explore over-the-top concepts.
Such as this CL65 AMG. Fitted with a bored-and-stroked high-pressure-turbocharged version of the V-12 engine found in the stock CL600, the coupe produces 604 horsepower and a rib-cage-flattening 738 pound-feet of torque between 2000 and 4000 rpm. Expressed in metric terms, the torque output is a round 1000 newton-meters of drivetrain-twisting force.
The really funny part of all of this is that the output had to be reduced somewhat in the interest of transmission life. There is another 200 or so newton-meters to be had here, and the aftermarket loonies will undoubtedly go looking for it. But Mercedes-Benz will not warrant that kind of exploration, even though this AMG car is covered by the Mercedes warranty with no transmission upgrades beyond new clutch discs and revised control logic. There are, however, beefed-up driveshafts and hubs farther downstream.
To get this kind of urge, AMG increased the cylinder bore by 0.6 millimeter and lengthened the stroke by six, ending up with 5980cc of engine displacement. AMG-spec forged pistons with thicker wrist pins fit inside the new holes, where they are cooled by an upgraded oil-spray system.
The combustion chambers were reshaped for a 9.0:1 compression ratio, and the intake camshafts have higher lift and longer dwell. Both turbochargers have larger housings and wheels and pump nearly 22 pounds of boost via a front-mounted air-to-water intercooler that is about 70 percent larger than the stock item.