Living with it: Mercedes E 300 de
Report 2: A Christmas road trip
Managing editor Stephen Errity took our E 300 de from London to Dublin, Ireland, and back over the Christmas and New Year holidays. The trip took in every type of road, from a long motorway run to North Wales to catch the ferry across the Irish Sea, to short suburban trips around Dublin to see family and friends, as well as a New Year's excursion to the Wicklow countryside (pictured) along winding rural routes and a diversion through Snowdonia on the return leg.
With temperatures remaining in single figures throughout, even the car's own dashboard display never promised more than about 20 miles of pure-electric running from a full battery, which is some way off the official claim of 30+ miles. We'd expect to see an improvement in warmer weather, though. Running the car primarily in Hybrid mode, charging from a domestic socket and occasionally using the engine charge function saw economy of 43mpg from a tank of fuel.
Elsewhere, the E 300 de boasts all the good points that apply across the E-Class range: it's a fantastically smooth, quiet and comfortable long-distance cruiser, with very supportive seats, an attractive, high-quality interior and an intuitive infotainment system linked to two large and clear dashboard screens. The hybrid system's torque boost, allied to an already torquey diesel engine and very smooth nine-speed automatic gearbox, makes the car very responsive when overtaking or getting up to speed on a slip road.
On the downside, you're always aware this is a pretty heavy vehicle and brake feel is vague at best due to the regenerative system. On the practicality front, the large box-shaped intrusion into the boot by the hybrid battery can be a real pain; you can probably count on fitting one large suitcase into the luggage area, rather than two as would be the norm with a large saloon. Those in need of true versatility should definitely look to the estate if they're considering an E 300 de.
The E-Class hybrid's cables can also be a problem; they arrive very neatly packed and wrapped with plastic in carrying cases that can be secured to the boot floor to stop them sliding around, but are difficult to pack away neatly again once you've opened them, and there's no dedicated cable storage area, so you end up just leaving them untidily splayed around the boot most of the time.
The overall impression of the E 300 de EQ Power from the two-week Christmas stint was a positive one, but that compromised boot means it's probably not one for buyers with young families to use as their main car. And it also served to reinforce our regular reminder that the quoted fuel-economy figures for plug-in hybrids should be viewed as 'ideal maximums', with the real day-to-day figures only likely to be around half as good.
Report 1: Introducing our E 300 de
Diesel plug-in hybrids like our new Mercedes E 300 de make a whole lot of sense. After all, the thing that’s most frustrating about many plug-in hybrids is the fuel economy you get when the battery power runs out.
Most petrol plug-in hybrids will only return around 35mpg or so, some rather less, so the prospect of a diesel car that’ll do 50mpg when your 34 miles of electric running is up sounds great to me.
Don’t get me wrong, I’m not glossing over the last few years of bad press and anti-diesel legislation that’s seen company-car tax and inner-city charging rise along with awareness of local NoX emissions and poor air quality.
Yet many modern diesels are just as clean as their petrol counterparts, and the benefits of better economy and lower CO2 are still persuasive for many high mileage drivers.
Which is why I’m so intrigued to find out how the Mercedes fares in terms of its efficiency over the next six months. We’ll have a chance to really test its real-world economy and find out for sure if this is a powertrain combination to advocate and encourage.
An official claimed electric range of 34 miles is one thing, but we need to know how far the 13.5kWh battery will take the big E-Class on electric power alone in cold and warm weather, and how motorway miles affects the range as well. And, of course, how economical the 2.0-litre diesel engine is thereafter, and what sort of economy you get if you plug in regularly and leave the car in default hybrid mode.
I even plan on investigating how much difference it makes to plug your route into the car’s nav when in hybrid mode, as the car will shuffle its power sources as it sees best according to your route. My commute covers some 30-odd miles each way, including around 70% on the motorway and the rest in crawling London traffic, so finding out how much variation there is hybrid mode with and without the info from the nav should be interesting.
I’m already equipped with a home charger, which means I can easily take advantage of the Mercedes' peak charging rate of 7.2kW. That means it’ll fully charge in under two hours; half the time it takes most other plug-in hybrids, including the E-Class’ nemesis, the BMW 530e.
Our car comes in the sportier-looking AMG Line trim, and the optional £595 Night package adds 18-inch alloys in the trademark Mercedes five-spoke design. That same pack also includes a gloss-black grille and exterior trim highlights, which look great contrasting with the standard Polar White paint.
The only other option on our E-Class is the £2,395 Premium package, which adds a memory function to the standard electric seats, and most notably the ‘Intelligent’ LED lights that I’d rate as one of the best pieces of safety kit of all, especially at this time of year.
But it's frustrating that the Mercedes doesn’t get standard adaptive cruise control. Even more so as it has all the fancy hardware and software required for adaptive driving, and uses it routinely when it adjusts the regenerative braking force in response to traffic ahead.
But if you switch on the standard, old-school cruise control, the car overrides all of the info streaming in from its cameras and radars, and accelerates mindlessly onwards at the chosen speed until you respond to a closing gap up ahead.
Speaking of odd omissions, there’s no keyless entry. That feature is only included on top-spec E-Class trims, which the plug-in powertrain isn’t available with. So if you want hands-free entry (which I always do) on an E-Class PHEV, you’re stuffed. Those frustrations aside, I already look forward to driving the E 300 de, regardless of the kind of journey I might be considering.
Yes, the electric range and fuel economy it achieves will be a critical gauge of this car’s relevance, but for any driver that does a lot of mileage and also spends time in town, the common sense behind it is clear. I can’t wait to see how it fares as the DrivingElectric team spend time with it over the coming months.
Mercedes E 300 de AMG Line
On fleet since: December 2019
Price new: £50,275
Price as tested: £53,265
Engine: 2.0-litre diesel plus 13.5kWh battery and electric motor
Combined MPG: 202mpg
Options: Night Package, including 18-inch five-spoke alloys and high-gloss black grille and exterior trim (£595), Premium package including memory seat function, parking pack with 360deg camera, wireless phone charging and Multibeam Intelligent LED headlights (£2,395)
Insurance: Group 44
Mileage: 990 miles
Any problems?: None so far