Needless to say that hybrid propulsion makes a lot of sense in powerful mid-size cars. Last but not least, with this hybrid, Mercedes just continues an old tradition: Mercedes built its first hybrid electric car in 1902 – the Mercedes Simplex.
The Mercedes hybrid system offers in town frugality and electric comfort without forgetting high speed performance and economy, wherein the Mercedes "normal" (Diesel) powered cars already truly excel.
We were therefore delighted when the dynamic PR department of Mercedes Benz Belgium Luxembourg put the new E300 BlueTEC HYBRID at our disposal for a test, keen as we are to discover how Mercedes understands hybrid mobility.
The results are very impressive, and clearly witness the high level of engineering this manufacturer with the good star has achieved.
Hans Knol ten Bensel
New E-class puts driving at even higher levels
Looking at the new E-class, we find the newly styled grille quite pleasing, with the more accentuated chromium surround, it stands out in a very distinctively. The proportions of the whole car are timeless, and this is maybe the biggest compliment we can make to the overall styling of the car, which breathes typical Mercedes "design language", both inside and out.
The interior of our test car was executed in pleasant light grey leather with gave it airiness and a light elegance, matched by the chromium accents of air vents, round instruments and accessories.
Iconic is also the central clock, reminiscent of the central clock which adorned the dashboards of the Uhlenhaut designed ponton Mercedes limousines, of which my father owned one in the mid fifties. I vividly remember sitting as a young boy in the middle of the rear bench watching the beautiful Kienzle clock set nicely in the beige dashboard upholstery.
On top of the dashboard was mounted a dark brown wooden inlay, which ran along the windshield bottom. Beneath the clock sat the impressive looking Blaupunkt radio with its custom styled speaker beneath it. You will never forget this design, and secretly you find that nothing ever will match its purposeful beauty.
This is pure nostalgia of course, as the shapes and volumes of this new E Class are beautifully balanced too. For classic car lovers, suffice to say that soon in these columns, an article will appear about the first “ponton” Mercedes.
When sliding behind the wheel, one enjoys the comfort of the well shaped seats, with the drivers' seat being adjustable individually in lateral support, backrest firmness, etc. The row of control buttons one sees on the photo below. This will let you find the exact level of support and comfort you prefer, and amply shows the masterful experience of the marque with the good star in making comfortable cars.
We already mentioned in previous tests the excellent ergonomy of the controls , intuitive to use and very logical, last but not least the excellent cruise control.
But let's turn now to hybrid driving, the Mercedes way. Put the steering column mounted lever in "D", release the handbrake and there you go, moving silently on electric power. But not for long. When one accelerates to more than crawling speed, the powerful 2,1 litre four cylinder Diesel is started up with a slight judder by the high power electric motor and gets purposefully to work.
In the "E" mode, the engine stops when coasting, and kinetic energy is transformed in electric power...
Doubtlessly Mercedes has found out that when somewhat more power is required, their efficient (Diesel) engines are ideally suited for the job, and only stop/ start and very slow driving requires the inherent efficiency of electric propulsion. Therefore, a smaller electric motor of a mere 20 kW has been chosen, with a relatively compact lithium-ion battery releasing again the stored energy.
The engine bay hardly betrays the hybrid system...
Indeed, the hybrid drive lay out of the Mercedes is very well thought out to say the least. It uses a rather small Deutsche Accumotive lithium-ion battery for its hybrid system, which is tucked away in the engine compartment.
one just sees the high power lines running along the McPherson dome...
Open the boot – it offers 505 litres of cargo space – and you’ll be greeted with a sight you won’t expect. There is no sign of a battery pack anywhere to be seen.
The engine is coupled to the classic 7- speed automatic transmission, found also in the other models of the E-class range. The only difference with the usual lay-out is that the torque converter has been replaced by a wet clutch, to allow the engine to be decoupled from the transmission swiftly and easily, especially for electric driving and “sailing”, of which hereunder further.
The engine keeps of course also the lithium-ion battery adequately charged, but does this only when one chooses the “E” mode and at lower speeds. Indeed, the battery receives much of its charging power from the kinetic energy one generates when driving: as a matter of fact, all too often, at constant speeds and as soon as one lifts the throttle, the engine shuts off, and the car just rolls along charging the batteries, with charging power of course increasing at higher speeds, and quite naturally also when braking.
This one can monitor easily when looking at the needle indicator in the left instrument cluster, which indicates the charging level when coasting and braking. The charging power is indeed substantial, as we discovered when driving in a anticipative defensive style in “E” mode, when the battery was charged exclusively on recuperated kinetic energy from 36 to 74 % on the distance between Brussels and Antwerp, in relatively fast but rather heavy traffic, with much coasting and moderate deceleration involved. The hybrid Merc certainly rewards a clever and anticipative driving style, and indeed consumption levels at higher speeds are very low indeed.
With this switch on the central console, one chooses between the "E" and the "Sports" mode...
When selecting "E" mode, the Mercedes will coast whenever and wherever possible, also right after the (cold) morning start, as soon as one lifts the throttle.
The car uses the kinetic energy truly very efficiently even in slow traffic, and the electric motor works as a dynamo, charging the lithium-ion battery. The energy recuperation system is cleverly calibrated, as the deceleration accentuates a bit around say 25-20 kph, anticipating a full stop, and therefore charges the battery even more effectively.
The car will invariably use its Diesel engine, when more power than the 20kW the electric motor delivers, is required.
But when one learns after some time to feather the throttle very cautiously, the system will reward this with using the 20 Kw electric motor for hundred(s) meters at a stretch and certainly in stop/ go traffic. Also parking manoeuvres will be absolved under electric power.
The engine will in these driving circumstances only start up when the system requires extra power for airco, ventilation or other ancillaries.
As said, the engine will also charge the battery from time to time when not enough kinetic energy is available to keep the batteries adequately powered, and this happens in the lower speed ranges up to say 70 kph.
At higher speeds, the kinetic energy is used exclusively, and the batteries are kept on charge when coasting or decelerating. The engine power is then only used for propulsion, and only when one lifts the throttle the wet clutch disengages, the engine stops and the kinetic energy recuperation starts.
When one pushes the throttle again, the electric motor starts up to smoothen out the power transition, and indeed, engine power sets in very subtly indeed. The system does this in "E" mode at speeds up to 160 kph.
The LED headlamps which adorn the new E class are very effective...
Of course, the E 300 is very much in its element on high speed “Autobahn” stretches. The massive power and torque of the engine, the balance, comfort and stability of the chassis all see to this.
And what's more, fuel consumption at these higher speeds is rigourously identical to a non-hybrid Merc, except that the hybrid will recuperate the kinetic energy below 160 kph and is therefore even more frugal...
When one chooses the “S” mode, the hybrid system only recuperates the kinetic energy of the car, but does not decouple the Diesel engine from the transmission when coasting or lifting the throttle, so no “sailing” function is available. Also the start/stop function is cancelled. In other words, the car just drives like a normal Mercedes, the car is indeed a true joy to drive sportingly.
With a little bit of foresight, one can still recuperate plenty of kinetic energy, and keep the battery power at very good levels. When you then push the throttle deeply, you have the 150 kW (204 hp) and 500 Nm (368 lb-ft) of the engine at your disposal, together with the power of the electric motor producing 20 kW (27 hp) and 250 Nm (184 lb-ft). This results in an acceleration from 0 to 100 kph in 7,5 seconds and a top speed in the region of 245 kph. Need we say more?
The 300E BlueTEC HYBRID turns in very impressive consumption data : 4,1 litres on 100 km is the official figure, with 109 g of CO2/km. We achieved during our test easily 4,5 to 4,3 litres/100 km, driving the car rather briskly.
A car to cherish…
Given the excellent workmanship and finish, the ingenuity, the superb dynamic qualities of this car, you can understand that we regretfully parted with this Mercedes,which is indeed a most clever proposition on the hybrid car firmament...and is a true joy to drive everyday again, last but not least giving you a very broad smile at the pump!
Hans Knol ten Bensel
One finds the good star...
with hybrid power...