Mercedes-AMG originally launched its '53' badged models with a 3.0-litre straight-six petrol engine and a 48-volt mild-hybrid system. And jolly nice they were, too.
Now, though, we're seeing the evolution of the 53 AMG models, and the GLE - in both SUV and Coupe forms - is the first to get the new AMG plug-in hybrid version using the '53' badge.
"With the GLE 53 hybrid as an SUV and coupe, we offer a unique combination of agility, driving pleasure and purely electric range. In addition to our high-performance-oriented E-Performance hybrid vehicles, these two GLE innovations form an additional pillar in our future-oriented portfolio. This means we are expanding our broad model range to include another attractive drive train variant and are addressing new target groups," said Michael Schiebe, chairman of AMG's board.
So, the 3.0-litre straight-six turbocharged petrol engine remains, but it has been upgraded and now produces an extra 14hp, bringing its total powertrain contribution to 449hp. The engine gets new software and an updated cooling system, but loses the electric turbocharger of the old version because, with the plug-in hybrid system, it just doesn't need it anymore.
That plug-in hybrid system uses a 100kW (136hp) electric motor, which is fed energy from a 31.2kWh battery. The motor uses permanently excited internal rotor synchronous technology, which Mercedes has brought in-house by buying up UK-based electric motor maker Yuasa. The motor produces a fairly massive 480Nm of torque all by itself, so it's just as well that the GLE 53 AMG has standard 4Matic four-wheel drive.
750Nm of torque
The maximum system torque output is actually 750Nm with both the electric motor and the petrol engine working together, and the maximum power output is 544hp - it's not so long that sort of figure would have been sufficient for a full-on 63 AMG badge.
The 0-100km/h time for this big SUV (or SUV-coupe) is just 4.7 seconds, and the top speed is, of course, limited to 250km/h. On a full charge, the electric system can drive the car on its own for up to 86km (or 87km if you're in the fractionally-more-aerodynamic GLE Coupe). There's 11kW AC charging for kerbside or three-phase home charging, and you can fast-charge the GLE and GLE Coupe 53 AMG on a DC public charger at speeds of up to 60kW, meaning just 20 minutes to get to 80 per cent state of charge.
The GLE and GLE Coupe 53 get some special styling tweaks, including a revised front air intake (which helps to feed that updated cooling system), special badges on the front wheelarches and the boot, and 21-inch alloy wheels behind which lurk an AMG high-performance brake system. That has internally ventilated brake discs measuring 400 x 38 millimetres on the front axle with six-piston fixed calipers and 370 x 32 millimetres on the rear axle with single-piston floating calipers.
Inside, the MBUX digital dashboard gets AMG-specific graphics and readouts while there's lots of extra toys including the electric panoramic sunroof, heated front seats, the adaptive high-beam assistant and smartphone integration. In addition, the switchable AMG performance exhaust system, the Burmester sound system, the memory package, the 360-degree parking pilot, the Keyless Go package and the blind-spot assistant are on board as standard.
Revised, quieter suspension
The chassis gets an updated AMG Ride Control system which uses air suspension, and Mercedes says that the car's noise-proofing has been upgraded so that it's suitably silent when running on electric power. There are new rear suspension dampers too, new software for the suspension control, a re-worked ESP system, fully-variable four-wheel drive and upgraded steering compared to the standard GLE.
There's also the AMG Dynamic Select driving modes system, which allows you to pick from settings including Comfort, Sport, Sport +, Individual and (our favourite) Smoothness, but there are also two new hybrid-specific settings - Electric (which does what it says on the tin) and Battery Hold, which will keep the battery topped up to 75 per cent charge as you drive, for later use when you get into town.
Irish pricing for the AMG 53 twins has yet to be announced.