Mercedes Benz E 300 de review

For those that regularly complete short trips, but often cover long distances as well, the idea of a diesel-PHEV seems like a good one. You get the benefit of long distance mile munching from the engine, and the use of electric-only power for those typical local trips. The trouble, there are very few diesel-PHEVs around. Mercedes is looking to change that. We test the Mercedes Benz e 300 de.

Review by Chris Lilly


There's a 2.0 litre diesel engine under the bonnet of the E Class on test, which is pretty typical of many an E Class. This one produces 194 hp and 400 Nm of torque - again, so far so normal. However, the 300 de also has an electric powertrain to complement the diesel unit. Adding to the engine's statistics are a 90 kW electric motor, producing 440 Nm of torque, and powered by a 13.5 kWh battery. Combined, the E 300 de produces 306 hp and 700 Nm of torque, good for a 0-62 mph time of 5.9 seconds and a limited top speed of 155 mph. It's a pretty quick car then, certainly with enough performance for most drivers. It feels quick too when you put everything into action. A prod of the throttle can get both systems working together, delivering all that power to the wheels. The electric motor provides instant pick-up, and when that starts to run out of puff, the diesel is nicely on song. Drive more sedately however, and the powertrain is extremely refined, as you would expect from an E Class. The nine-speed automatic keeps gear changes silky smooth, and it's a fine engine/motor combination, one that proves a Jack of all trades. Motorways, urban routes, country roads; it doesn't matter where you are, the E 300 de has a set-up to suit.


The E 300 de fits nicely into the E Class range and is a consummate mile-muncher. You can cruise along at motorway speeds with ease and refinement, as the Mercedes takes the strain. There are sharper cars to driver in this class, but the E 300 de is a well balanced machine, with a good compromise between dynamic and comfortable driving modes. There's a little body roll when cornering hard, but the E 300 de remains composed even when pushing on, and the weight in the steering is excellent.


From the outside, the E 300 de looks almost identical to any other conventional E Class, with only a few small clues as to the plug-in abilities the Mercedes offers. Some very discreet badging, blue brake calipers, and the inlet port on the rear bumper are the key differentiators. All this means that if you like the E Class shape - and there's very little to dislike about the mid-sized exec's design - you'll like the PHEV version. Thanks to some clever packaging, the interior space is identical to normal petrol and diesel versions for passengers. Those front and rear have an excellent amount of space, and some of the comfiest seats around. Unfortunately the same identical space comment can't be said about the boot. There's a rather noticeable block taking up a fair proportion of the load area, so if you a driver that regularly fills the boot, you may struggle with the E 300 de. It's still practical enough for most uses, but you could add a couple more suitcases in the back of a non-plug-in E Class.


Mercedes Benz E 300 de interior

The current Mercedes interior is excellent, and the E Class is amongst those to benefit from it. Drivers get two large screens joined in one large unit. It's striking, and backed up by one of the best systems on the market - MBUX. It's an intuitive system, with natural voice commands available, good quality graphics, and an extensive set of functions. Controls via the steering wheel are brilliant, with the right set of buttons controlling those elements on the driver's instruments, and the left controlling the infotainment system. There's a touch sensitive central 'button' that can be swiped and pressed for clever controls, and the whole thing works beautifully. The rest of the systems feel solidly put together and with top quality materials. It's a cabin that makes occupants comfortable and relaxed, and is a match for anything in its class.


The key reason for the E 300 de is it's fuel economy, and the Mercedes doesn't disappoint. Official figures are an electric only range of between 28 and 31 miles depending on specification, and fuel consumption topping out at 201.8 MPG. As with all PHEVs, the fuel economy score is largely redundant, and can either be comfortably beaten or not even close to achievable, depending on usage and charging. I found that the E 300 de will comfortably complete 24 miles on a charge, and that wasn't in urban stop/start conditions. I'd expect a realistic figure to be closer to 30 miles if largely kept in cities/towns/villages in electric mode. Fuel economy is extremely good even on longer trips, when the car manages to recharge the battery under braking and improve electric range. After almost 250 miles and starting on one full charge, the trip computer was showing 74 MPG - and that's having held around three quarters of the charge for later use. It really combines the long distance capabilities of diesel with benefits in built up areas that only electric power can bring.


As you would expect from a PHEV, there are a number of systems to help make the most if its potential efficiency. Brake energy recuperation tops up the battery under braking. Driving modes include Eco, Comfort, Sport, Sport+, and Individual, while electric driving modes see Hybrid, E-Mode, E-Save, and Charge available. The E Class can make use of the driver assistance systems when driving in Economy or Comfort mode to automatically get the highest efficiency scores. By using radar sensors, cameras, and the navigation system, the powertrain management system can take account of topography, routes, and traffic for the best economy. There are driver coaching tips given when travelling, and the Mercedes has recognised the benefit of regular charging by including a 7.2 kW on-board charger. This means that when connected to a typical 7 kW home or public charge point, it will only take around an hour and a half for a full charge. Charging the 13.5 kWh battery is carried out via a Type 2 inlet on the rear bumper.


The E 300 de is available as both a saloon and estate, and in one of three trim levels - SE, AMG Line, and AMG Line Premium. Entry level SE includes 18-inch alloys, agility control suspension, drive mode select, LED healights, automatic wipers and lights, keyless entry & start, heated front seats, leather trim, cruise control, touchpad controller, 12.3-inch infotainment system, and 12.3-inch digital driver's instruments. AMG Line tested includes AMG styling, active parking assist with front and rear sensors, a comprehensive suite of safety systems, climate control, sports seats AMG steering wheel, and black open-pore ash wood trim. The specification also saw Premium Plus pack added, including a 360-degree camera, multibeam LED lights, Burmester surround sound audio system, wireless phone charging, and panoramic glass sunroof. Also fitted were a Comfort pack incorporating Air Body control and Nappa leather upholstery, a Driving Assistance pack, and Night pack.


Mercedes Benz E 300 de rear

Although diesel isn't particularly fashionable with sales in serious decline, there is still a place for it with high-mileage drivers. Combining the fuel efficiency of diesel on long-runs with the electric efficiency where diesel doesn't work well - stop/start traffic, short trips etc - the Mercedes Benz E 300 de performs excellently. It's a one-car solution for a great number of buyers out there, particularly company car drivers.

Model tested: Mercedes Benz E 300 de AMG Line
Body-style: Executive saloon
Engine / CO2: 2.0 litre diesel with electric motor / 41 g/km

On-road price: AMG Line from £50,195. Price as tested £60,860.
Warranty: Three years / unlimited mileage
In the showroom: Now
Review rating: 4.0 Stars

Chris Lilly

Author:Chris Lilly
Date Updated:27th Nov 2019

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