Mercedes E300 Hybrid

What is it?

The first in a pair of new hybrid powered E-class models – the Mercedes-Benz E300 BlueTec Hybrid. Aimed primarily at European markets, it sets out to combine the typically high fuel economy of a modern day common rail four-cylinder diesel engine with the added fuel savings brought on by electric power.

Planned to go on sale in the UK in October in both saloon and estate body styles, the E300 BlueTec Hybrid mates the existing E250 CDI’s twin-turbocharged 2.1-litre combustion engine delivering 201bhp with a relatively small electric motor mounted in the forward section of the gearbox housing developing 27bhp, giving it a combined system output of 228bhp.

Energy for the electric motor is provided by a 0.8kWh lithium-ion battery that, like in the S400 BlueEfficiency Hybrid, is mounted up front in the right hand corner of the engine bay. There is no plug-in function – at least, not yet, so energy for the battery, which comes from Continental, is generated exclusively on the run during periods of trailing throttle and under braking. All up, the hybrid components, including the motor, battery and electronic management system, are said to weigh 100kg, endowing the new car with a kerb weight of 1840kg.

Drive is channelled to the rear wheels via a reworked version of the German car maker’s widely used seven-speed automatic gearbox that forgoes a traditional torque converter for a wet start up clutch similar to that used AMG on MCT equipped models. In line with developments brought to more conventional models, the so-called 7G-Tronic Plus unit supports automatic stop/start and offers the choice between either ECO or Sport modes.

What’s it like?

Accept that the E300 BlueTec Hybrid’s small battery is never going to allow it to run on electric power alone for extended periods or provide a significant increase in overall performance and it proves quite impressive.

The synchronous motor, supplied by Bosch, is used primarily to set the car in motion from standstill and for manoeuvring during parking.

With 184lb ft of torque available instantly, it glides away smartly and silently. You have to be gentle with the throttle, but the E300 BlueTec Hybrid can be made to run around town on electric power alone – albeit only for distances of up to 0.6 miles. The electric motor has been programmed to work alone at speeds at up to 22mph, at which the diesel engine cuts with a subdued but, for the most time, noticeable rattle of start-up vibration.

Integrated into the drive process, the diesel engine provides solid if not startling levels of performance. With 369lb ft of torque served up at 1600rpm the four cylinder unit offers up a reasonable level of shove on light to middling throttle loads.

As you back out of the throttle the diesel engine shuts down as part of a “sailing” function aimed at maximising fuel savings at speeds up to 100mph.

Overall refinement is sound – better than the E250 CDI, although the wet clutch can’t match the smoothness of the torque converter equipped automatic gearbox from step off, leading to some undesirable driveline shunt in stop-start traffic.

Put your foot down and the electric motor supports the efforts of the diesel engine, providing a boosting effect that endows the E300 BlueTec Hybrid with an impressive turn of speed. Mercedes-Benz claims 0-62mph in 7.5sec and a top speed of 150mph for the saloon and 7.8sec and a top speed of 144mph for the estate.

It is the fuel consumption figures, though, that its hybrid driveline engineers are most proud of. With a combined average of 67.3mpg for the saloon and 64.2mpg for the estate, the E300 BlueTec Hybrid is described as the most fuel efficient car in its class, offering a 10.8mpg and 10.9mpg improvement over the already frugal E250 CDI. This translates to CO2 emissions of 109g/km and 116g/km respectively. On paper it also beats the ActiveHybrid5 and A6 Hybrid.

With measured driving over 116 miles of country roads and autobahns, we managed to better the E300 BlueTec Hybrid’s official consumption, averaging 65.7mpg. Don’t expect these sort of figures in every day driving, but there’s no doubting the E300 BlueTec Hybrid’s eco credentials.

Should I buy one?

It’s already becoming clear that hybrids are more than just a passing fad. The E300 BlueTec Hybrid also proves that car makers are beginning to understand how to best realise their fuel saving potential. It doesn’t bring anything too radical in terms of technology. But by sticking to a relatively simple formula, the new Mercedes-Benz manages to provide small but valuable real world savings.

Look past is headlining consumption figures and the best thing about it is just how conventional it is to drive. That, and the fact that it manages to offer the same generous accommodation and luggage capacity as its more conventionally powered siblings. It won’t be a hit among private car buyers but expect to see it appeal to fleet buyers seeking something out of the ordinary.

Mercedes E300 Hybrid

UK pricing is yet to be announced but German prices start from €51,794 (£43,275) for the saloon and €55,007 (£45,960) for the estate model.