Diesel Powertrain Leads Way With Mercedes Coupé

Mercedes-Benz continues to champion the under-siege diesel powertrain, at least in Europe, with its latest GLE Coupé and Mercedes-AMG SUV.
Making their global debut at the 2019 Frankfurt Motor Show (IAA), the cars boast six-cylinder diesel engines in the form of the 350 d and 400 d claiming a combined fuel consumption of between 35mpg (29mpg US) and 37mpg (31mpg US) and combined CO2 emissions of between 221-197 g/km. One gasoline engine will be offered in the range-topper Mercedes-AMG GLE 53 4MATIC+ claiming 30mpg (25mpg US) on the combined cycle with CO2 emissions of 212 g/km. Mercedes plans to add a plug-in-hybrid version with a practical, locally emission-free range as for the GLE SUV.
It’s clear that the carmaker remains focused on diesel sales in European markets where the powertrains still retain the best climate friendly credentials when considering energy production mixes in the differing states. The two diesel powered GLE Coupé models employ the OM 656 six-cylinder in-line engine in two output levels, as the GLE Coupé 350 d 4MATIC rated at 270bhp and 442ft-lbs of torqe and as the GLE Coupé 400 d 4MATIC with 327bhp and 516ft-lbs of torque. In both versions, the engine already complies with the Euro 6d standard (RDE/Real Driving Emissions Step 2) using the AdBlue additive though an additional special ammonia slip catalyst in the exhaust. Mercedes claims this allows dosing of the AdBlue reducing agent more closely aligned with the individual driving characteristics because any excessive ammonia surplus in the second converter is broken down further.
Performance addicts get the choice of the gasoline mild hybrid AMG six-cylinder in-line engine with twin turbocharging and EQ-Boost achieves 433bhp and an additional temporary 20bhp of electric output. It also offers hybrid functions such as overrun mode.
ADAS features include the Active Distance Assist DISTRONIC with Route-Based Speed Adjustment. If the driver switches it on the GLE Coupé can react to information from Live Traffic, in the ideal scenario even before the driver or the radar and camera sensors can perceive this traffic obstruction. When a traffic tailback is detected, the speed is reduced to about 62mph as a precaution unless the driver specifically decides otherwise.
When driving in a tailback, Active Stop-and-Go Assist operates lane keeping and maintaining the safety distance at speeds up to around 40mph and moving off can be automatic up to one minute after coming to a stop. On multi-lane roads, Active Steering Assist is able to function on highways at speeds under 40mph the detecting lane markings and applying swarm intelligence to take its bearings from vehicles in the surrounding area. If no such vehicles or markings are detected, the GLE Coupé will take its bearings from the vehicle ahead.
— Paul Myles is a seasoned automotive journalist based in London. Follow him on Twitter @Paulmyles_