The ultra-modern engine line-up in all GL-Class models provides superlative drive comfort and compelling performance coupled with superior fuel consumption figures compared with other vehicles in the class. Alongside the 165-kW/224-hp V6 engine in the GL 320 CDI, the range of diesel models includes the new-generation high-performance V8 diesel in the GL 420 CDI, which now has an out-put of 225 kW/ 306 hp and maximum torque of 700 Nm. Both diesel-powered versions undercut the EU 4 limits and feature a maintenance-free diesel particulate filter. In addition to the newly developed 5.5-litre, 285-kW/388-hp engine in the GL 500, launched earlier in the new S-Class, the second unit in this ultra-modern V8 family of engines is celebrating its world premiere in the GL-Class. In the GL 450 the 4.6-litre engine develops 250 kW/340 hp. Both engines also fulfil the stringent EU 4 limits (USA: LEV II standard).

All Mercedes-Benz GL-Class engine variants come with the standard-fit 7G-TRONIC seven-speed automatic transmission with DIRECT SELECT. Excellent performance and low fuel consumption result not just from the perfect combination of ultra-modern engines with 7G-TRONIC and the friction-optimised powertrain. Another important factor is the comparatively low gross vehicle weight thanks to the unitised body and the excellent aerodynamics (Cd 0.37) for such a large vehicle.