[2] While the M273 was naturally aspirated, the M278 features twin turbochargers from Honeywell, one per cylinder bank, producing 0.9 bar (13 psi) boost pressure in most configurations.

[2] The entire M278 lineup avoids the United States Gas Guzzler Tax, a first for V8 production engines from Mercedes-Benz.

The GL-Class, besides the GL550 above, also features the GL450 trim that carries a detuned version of the 4.7 L engine making 270 kW (362 bhp; 367 PS) and 550 N⋅m (406 lb⋅ft)[6] For 2014 S-Class models (chassis code W222), power is increased to 335 kW (449 bhp; 455 PS) at 5,250 rpm, while torque remains at 700 N⋅m (516 lb⋅ft) between 1,800-3,500 rpm.

[13][14][15][16] These engines are mated to the AMG Speedshift MCT 7-speed semi-automatic transmission, which replaces the 7G-Tronic's torque converter with a wet clutch pack.

[17] Note that this MCT 7-speed can handle considerably more torque and is not the same unit as the dual-clutch transmission found on the Mercedes-Benz SLS AMG.

[19] The third variant, designated M152, is a naturally aspirated derivative of the M157 engine, sharing the same displacement, direct injection, and many other features.