Is Mercedes-Benz's diesel hybrid SUV the (near) future?

Monday, 16 December 2019

Snow business in the new Mercedes GLE coupe.

Here's the dirty drawback of our favoured driving choices: in many instances, the SUVs, crossovers and one-tonne utes we've elevated to sales stardom are negating emissions reduction aims. Utes especially.

That's no surprise, really, but it's a topic that falls into focus with assessment of a version of a core Mercedes.

The GLE 350de is yet to be signed off for New Zealand, but is worthy of consideration in that it sets out to clear the air ahead of introduction, in Europe, of passenger vehicle emissions standards that are being considered for implementation here.

The best of both worlds? The Mercedes-Benz GLE 350de packs an impressive 100km+ of electric-only range for daily commuting.

What drives it? EU mandate for a fleet-wide average emission target of 95 grams of CO2 per kilometre. It's not about pushing existing product off the road (or perhaps even hit utes here, as they are considered commercial vehicles) but certainly sets a different tone.

**READ MORE:

While it misses out on the superb diesel inline six of the GLE 400d, the 350de's four-cylinder hybrid powertrain still pumps out and impressive 235kW and 700Nm.

* First drive road test review: Mercedes-Benz GLE coupe

* Road test review: Mercedes-Benz GLE 400d

The GLE 350de will charge to 80 per cent in just 20 minutes.

* Why does NZ have a mental block about plug-in hybrids?

* Five plug-in hybrid luxury SUVs**

The 350de adds dedicated PHEV information to the GLE's excellent MBUX infotainment system.

Claimed economy and emission numbers more commonly seen from compact city cars is the 350de's star quality, as well as the fact that it does it without losing traditional SUV strengths by using a technology Kiwis know well: a plug-in hybrid drivetrain.

Benz is among several makers sold on backing PHEV tech in this size of vehicle instead of going full electric, though that might ultimately occur. Whether you like it or not will ultimately cease to matter.

When not running on electricity alone, Mercedes claims the GLE 350de will sip diesel at a combined average of just 1.1L/100km.

It has to happen because, as popular (and profitable) as SUVs and crossovers of all shapes and engine sizes have been, they've become too much of a good thing. This rising popularity almost always occurs at the expense of smaller and lighter cars so has caused CO2 levels to rise.

Makers that have found themselves with SUV-heavy line-ups will have the most trouble achieving the next emissions targets, which phase in next year. Fines await those who fail to fall into line. So, two options: drop their less planet-friendly editions or create vehicles that are eco-friendly enough to bring the fleet average down.

The 'EQ Power' badge covers all of Mercedes' PHEV cars, while 'EQ Boost' will signify a mild hybrid system.

The 350de is just one pawn in the great game. Benz sees EVs and PHEVs accounting for around 40 per cent of its total sales by 2025, but admits the EV component is a guess-timate, the true speed of EV uptake proving difficult for even the world's oldest car maker to judge.

Since it also reckons engines will be around for a long time yet, in addition to creating a host of full electrics, headed by the EQC, it will push 48V mild-hybrid vehicles under the EQ Boost banner, while plug-in hybrid systems will be known as EQ Power.

Christolph Grossman, technology spokesman for the 350de, portrays a 'best of both worlds' beauty to his drivetrain. As well as offering reduced CO2 emissions, plug-in hybrids can help showcase the benefits of fully electric powertrains.

'We chose a four-cylinder because on a normal day-to-day drive the customer will likely run in pure electric because of the battery's big range and then, for the longer commute, use the diesel for its high efficiency.'

The GLE 350de packs a 143kW 2.0-litre diesel with a 100kW electric motor and a lithium battery pack that, with a total output of 31.2kWh, is four times larger than the battery in the previous GLE hybrid and basically as large as some driving small EVs.

Pure electric range is impressive for a PHEV - 106km on the NEDC cycle, 90-99km on the stricter WLTP protocol - while Mercedes-Benz claims a combined average fuel consumption of just 1.1L/100km, with a CO2 output of just 34 grams per kilometre. To put this into perspective, the GLE 400d sister model that uses a 3.0-litre six-cylinder turbodiesel sips at a rate of 7.4 L/100km, with emissions of 195g/km.

Also affected by a high-efficiency exhaust system, the 350de's CO2 count is within a range that would award Benz emissions 'supercredits' and achieve ultra-low emissions vehicle status.

Don't think being a miser makes it meagre. Yes, the 350de's on our drive route were less sprightly than the 400ds and AMG 53s, yet with a combined outputs of 235kW and 700Nm and 100kmh from a standstill in just 6.8 seconds, it's not slovenly. In EV mode top speed is a generous 160kmh, rising to 210kmh with the engine involved.

It also offers impressive AC and DC charging solutions, with the latter able to recharge the battery pack from 10 to 80 per cent in just 20 minutes, or 30 minutes from 10 to 100 percent. From a wallbox, it'll take 90 minutes for a full charge while from a conventional power socket it will require about five hours. There's a 7.4 kW onboard charger and regenerative braking to juice up while on the go. It is able to take Type 2 and CCS charging connections and the sat nav can seek out compatible charging bays.

The electrified powertrain hasn't hurt the GLE's capability as a load-lugger, either. It retains the regular editions' maximum towing capacity of 3500kg. And although Benz had to modify the rear axle to fit the battery, it's still a roomy five-seater. Also, though no pricing has been signalled, the previous hybrid placed between the biggest diesel and the AMGs.

So cool, right? And now you're doubtless wondering about when we might see this drivetrain in either GLE body format.

The NZ office seems interested but, potentially, it's Australia's decision. Our countries share model lines for sake of expediency but regional HQ in Melbourne ultimately calls the shots.

Their man on the launch suggested a petrol engine PHEV is more useful across the Tasman than the Europe-minded diesel out now. That's a work in progress but Grossman says it's a cinch. It's just the timing that's up in the air.