LIKE with so many things that originated in America, petrol-electric hybrid cars have eventually found their way to Europe. With the desire to reduce emissions and extend a petrol car’s range, Honda and Toyota added a parallel electric motor and battery system to assist in the propulsion duties.
By and large the systems work well, although in the real world the savings can be modest if you’re not prepared to modify your driving style accordingly. But petrol in general and petrol-electric hybrids in particular have been playing second fiddle to diesel powered cars in Europe. Unlike our American cousins we embraced the fuel a long time ago. As such, what would be better for our tastes is a no compromise diesel-electric hybrid.
Like buses, the latest offerings have all come at once, with Peugeot-Citroen and Mercedes bringing a small but promising selection of cars to market at the same time.
Continuing the no compromise theme, it’s Mercedes’ E-Class model that promises all the usual features and creature comforts of its maker’s volume-seller, but with the added bonus of an unobtrusive hybrid system to boost range and economy over and above a conventional diesel model.
It’s clear that Mercedes has studied the competition and learnt from its mis-steps. During a varied mix of real world driving routes petrol hybrid models don’t always match their official on-paper economy figures. The belief is that diesel hybrids will get a lot closer and, crucially, with less effort on the part of the driver. In summary, you should be able to drive a diesel hybrid E-Class like a pure diesel model and still reap the rewards of low consumption.
Diesel cars have another trick up their sleeves over their petrol rivals in the shape of superior performance over long distances and at high speeds. It’s a given that, if you do plenty of motorway miles, diesel is better for your wallet than petrol. This is also the case with hybrid cars – low engine revs and superior levels of low down torque make for a more relaxed and efficient way of travelling. And that’s before you start adding a battery and any fancy electronics.
With its E 300 Bluetech Hybrid, to give it its full name, Mercedes has adopted a low-key approach to hybridisation. A small 0.8kWh lithium ion battery is located in the engine bay of the E-Class, while an equally modest 27 horsepower electric motor adds the extra, silent motive power. The result is a helpful addition to the car’s 2.1-litre twin turbo diesel motor, and brings total power output to 228 horsepower.
Why no plug-in electric option like some rivals? In a nutshell, Mercedes views this E-Class as a useful and cost effective step in the right direction. Full-blown hybrids with large batteries usually suffer with reduced load space and increased weight. This E-Class is being sold in both saloon and estate form with no discernable reduction in load space, and it’s expected that a more expensive plug-in hybrid offering an increased electric-only driving range is in the pipeline.
For now, this E 300 offers largely company car drivers the ability to reduce their financial outgoings without compromising the refinement and space of a premium-size car. At a basic level the E 300 drives just like a E 250 CDi diesel, which is a good thing as it means you don’t need to adopt a super-frugal driving style to extract a few more miles per gallon. Officially the car returns an impressive 67.3mpg in saloon form and, disappointingly for the taxman, emits a lowly 109g/km CO2.
These figures are partly the result of the car’s ability to start and pull away in electric –only mode and continue for around half a mile if driven gently – shuffling along in city traffic springs to mind. At the other end of the spectrum, consistent higher speed running allows the car to ‘sail’ as Mercedes describes it when you lift off the throttle on flat or downhill sections, as the diesel engine is switched off for short periods of time.
It’s in these situations that the car’s battery contributes to the proceedings, adding welcome extra motive power, allowing itself to be topped up during braking actions and adding a subtle ‘push’ alongside the diesel motor when extra acceleration is required.
Techno-savvy drivers will no doubt get excited by what’s under this E-Class’ bonnet but for then rest of us the key issue is that the technology just works. Diesel engine start up and shut down on the move is barely noticeable, while the car’s seven-speed auto gearbox mirrors the smooth performance of its regular petrol and diesel counterparts.
Granted, there will be a small price premium over a diesel-only E-Class, but the logic is that you’ll make enough savings through fuel and tax outlay to make the sums add up. It’s also fair to say that such a car will attract early adopters, where making a statement is often the priority not the cash saving.
Either way, this diesel-hybrid Mercedes offers executive level buyers a genuine choice in the alternative fuel market. It’s capable of delivering on its eco credential promises and offers a promising insight into the future of hybrid motoring.
FACTS AT A GLANCE
Model: Mercedes-Benz E 300 Bluetech Hybrid saloon, from £45,000 approx (on sale end of 2012).Engine: 2.1-litre diesel unit plus electric motor developing a combined 228bhp.Transmission: 7-speed automatic transmission as standard, driving the rear wheels.Performance: Maximum speed 150mph, 0-62mph 7.5 seconds.Economy: 67.3mpg.CO2 Rating: 109g/km.