The GLE Coupé has an agreeable driving environment: the high seating position affords a commanding view out front, while higher-grade materials create a genuinely upmarket feel throughout. Leading the new features is an optional 45x15cm head-up display. Active Stop-and-Go Assist, which permits semi-autonomous driving in traffic jams, is also among a wide range of driver assistance systems offered.
Despite the increase in external dimensions, accommodation remains much the same as before; shoulder room in the front has increased by 21mm, but other measurements go largely unchanged. That said, the new GLE Coupé is imminently practical in spite of its swoopy roofline and liftback-style tailgate, offering more than adequate space for five adults and 655 litres of boot space – 25 litres more than the regular GLE, no less. In a move that aids the loading of heavy items, the loading lip is now positioned 59mm lower than before.
The basis for the new GLE Coupé is Mercedes' MHA (modular high architecture) platform, as used by the latest GLE and GLS. This is claimed to offer an impressive 33% increase in rigidity over the structure used by the original model, thanks in part to the adoption of cast-aluminium nodes for the front and rear suspension mountings.
The new GLE Coupé will be sold in the UK with a choice of petrol, diesel and diesel-electric plug-in hybrid drivelines. All come mated to a standard nine-speed automatic gearbox and Mercedes' 4Matic four-wheel drive system, which in its latest form offers fully variable apportioning of drive between the front and rear axles as standard.
The sole petrol unit, a turbocharged 3.0-litre in-line six-cylinder with 429bhp and 382lb ft, features in the AMG GLE 53 Coupé. The diesels use a turbocharged 2.9-litre in-line six-cylinder unit, developing 268bhp and 442lb ft in the GLE 350d and 325bhp and 516lb ft in the GLE 400d.
It’s the plug-in hybrid powertrain in the GLE 350de driven here that represents the biggest advance, though. It runs a turbocharged 2.0-litre four-cylinder diesel engine in combination with a gearbox-mounted electric motor for an overall output of 316bhp and 516lb ft – sufficient to endow it with a 0-62mph time of 6.9sec.
The two power sources are terrifically integrated in hybrid mode, to the point that you’re scarcely aware which is being used in urban driving conditions. With a deep reserve of torque, the delivery is engagingly flexible, giving the GLE 350de outstanding cruising qualities. That said, there are times when the engine has to work quite hard to deliver the performance requested and therefore is quite vocal.
With a 31.2kWh lithium ion battery housed beneath the floor of the boot, the GLE 350de delivers a class-leading official electric-only range of between 51 and 62 miles at speeds up to 100mph, so you can switch into electric mode and complete extended commutes without running out of juice. As a result, its combined WLTP fuel consumption is rated at between 256.8mpg and 217.3mpg – figures you won't replicate in real-world driving but which endows the most economical of the new GLE Coupé models with a truly tax-busting CO2 rating that should make it attractive to company car buyers.
The amount of electric energy regenerated under braking and coasting is very impressive. It's achieved via all four wheels rather than just two, as on earlier plug-in drivetrains offered by Mercedes. Full recharging of the battery, meanwhile, can be completed in half an hour at a rate of up to 60kW – faster than any rival.