Car reviews - Mercedes-Benz - E-class - E300 BlueTEC
No-compromise hybrid technology, stealth coasting mode, sharp step-off acceleration, luxury feel to cabin, good handling, clever regenerative braking system
Room for improvement
Hybrid is a big $10,000 step up, ride a little compromised on 19-inch alloys, foot-operated park brake, long queue to get one
24 Jul 2013
By BARRY PARK
WE’RE not doing anywhere the 160km/h limit to shift the E-Class hybrid into sailing mode instead we’re coasting along a flat bit of road doing the 60km/h speed limit.
We know we’re coasting under electrons alone, too, because the large relief image of the car on the centre console display that shows the ebb and flow of electricity and diesel fuel is showing a blacked-out engine, while stylised electricity is trickling from the battery to the rear wheels.
Sailing is the new E300 BlueTEC Hybrid’s biggest party trick, saving fuel even when you’d expect the four-cylinder, twin-turbo diesel engine under the traditional-looking E-Class bonnet to be working away lightly at keeping the mid-size luxury sedan rolling.
But there’s the thing in a world where the word “hybrid” equates to compromise – be it in the driving experience under jerky regenerative brakes and heavy suspension loads, or in terms of versatility as battery packs eat into valuable boot space, the E-Class hybrid makes absolutely none – other than a big $10,000 price premium.
From the outside, there’s no telling the E-Class is any different to any other conventionally-engined, low-specification model already plying the road, apart from the “BlueTEC Hybrid” in bold, capital letters across one corner of the boot lid.
Open the door and jump behind the wheel, and it even looks the same as any other E-Class, and apart from a missing centre console-mounted “Eco” button in the similarly equipped, non-hybrid diesel-engined E250 CDI and an extra hybrid display on either the centre console or in the instrument cluster, nothing is different.
It still looks the same, has the same push-button start function, the same confusing column-mounted gear shifter for the seven-speed automatic gearbox, the same steering wheel, the same foot-operated parking brake, the same Teutonic feel of quality ... you get the idea.
Driving it, too, is no different. OK, the engine doesn’t fire up when you push the start button, but instead the dash lights up just as though it had. Pull down on the right-hand stalk to tip it into drive, and you can creep away under light acceleration using nothing but the battery and electric motor.
You will notice something here that’s unusual, though – the brake pedal feels a bit long. Benz has worked hard to ensure that the regenerative braking in the E-Class, which reverses the electric motor to turn it into a drag-inducing generator, feels just like a normal pedal.
What they’ve done is create a brake pedal with two modes. Instead of a traditional regenerative braking system, that has the hydraulic brake system connected alongside the regenerative one, Benz has allowed the electric braking system to have its way first.
As you start to stand on the brake pedal, instead of pushing fluid to the calipers hugging bigger, cross-drilled discs on the front wheels and the ventilated discs on the rears, the regenerative braking alone is activated.
Rather than have a soft-feeling pedal, The Mercedes engineers have replicated brake feel with a rubber block that gives resistance.
Push past the tipping point for just the electronic braking alone, and the regenerative and conventional braking systems work together to draw the E-Class hybrid comfortably to a stop.
It gets over the juddery feeling of more primitive regenerative braking systems that are difficult to modulate and give a wooden feel to the pedal. That’s not saying the E300 BlueTEC Hybrid’s AMG-sourced brakes don’t lose some feel compared with a conventional system – they do feel ever so slightly harder than on the E250 CDI we just jumped out of – but it’s damn close.
You might also notice a slight whine under braking as the motor-turned-generator turns the momentum normally lost under brakes into electricity.
Driving is improved over the conventional car, and it’s all down to the responsiveness of the E-Class hybrid from a standing start.
The conventionally engined E250 CDI has an idle-stop system that shuts down the diesel four-pot to save fuel when the car is either caught in traffic or stopped at the traffic lights.
Jump quickly off the throttle while the engine is stopped, and it is possible to catch the Benz asleep as the diesel powerplant rattles back into live with a shudder and sends power to the rear wheels.
However, the hybrid system has an electric motor that improves on the 150kW of power and 500Nm of torque that the engine taps once a few revs are on board.
The electric motor only develops 20kW of power, which is nothing, but delivers a big serve of 150Nm of torque almost from rest, which is significant.
Where the E250 CDI stands and shakes while the sedan’s electronic smarts realises you want to get going again and ticks through the list for the restart process, the E-class hybrid taps the electric motor to get things rolling the instant you’re on the throttle. No idle-stop lag, then.
As an aside, if you sneak into the driveway under electric power alone at night, put the car in park, set the handbrake and forget to switch the car off, as soon as you pull on the door handle the engine will fire back into life as a last-minute wake-up call that the Benz is still alive.
The E-Class hybrid’s suspension is tuned for comfort rather than handling, and the extra 100 kilograms the hybrid system stacks mainly over the low-profile 19-inch front wheels is well disguised.
However, hit a big bump such as a pothole – we did hit one – and the suspension crashes heavily as it struggles with the extra load. At highway speeds, running over small imperfections such as road reflectors sends a slap through the car.
The Benz uses the same seven-speed automatic transmission as the rest of the E-Class range, and shifts smoothly enough, although still lacks a little of the refined edge of a certain competitor’s slick-shifting eight-speed unit.
But what about those all-important fuel savings that the hybrid system delivers? The hybrid E-Class is meant to save 0.7L/100km over its cheaper, conventionally engined E250 CDI’s 4.9L/100km.
We didn’t see that, posting figures that ranged between 7.1-7.9L/100km on our 200-kilometre drive that looped through Melbourne’s central business district to the city’s northern fringes. Other drivers posted results slipping into the high 6s, but not us.
That compares with a 7.9L/100km average in a E250 CDI test car we handed back this week.
Admittedly, we drove the E300 BlueTEC Hybrid just like any other car, and the diesel engine on our test vehicle was barely run-in, also which hurts fuel use.
We’d be interested in seeing what the car can do on familiar roads and routes.
However, the first hybrid Benz to grace our roads – and the first diesel-electric passenger car to do so, if you discount the many diesel-engined trucks in Australia already using the technology – shapes up well in the scheme of things.
According to Mercedes-Benz, the E-Class won’t cost any more than a conventional mid-sized three-pointed star car, meaning it won’t even hurt you in the workshop, let alone at the fuel pump.
It’s just a shame that, after reading this, you decide you really, really want to add one to the driveway. Mercedes-Benz already has about 60 buyers lined up for the car – about the remainder of this year’s allocation – so you had better be prepared to wait.
At least it gives you time to save up that extra $10,000.
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