Mercedes-Benz has been significantly reducing emissions and fuel consumption and emissions in all its vehicles for many years. Now the latest ultra-clean model has arrived in Australia, and the Mercedes E 300 Hybrid is the best of them all.
This is the first car in Australia to combine electric hybrid technology with a diesel engine. At least one other maker sells diesel-electric hybrids in Europe, but their steering wheels are on the wrong side for Australia. To its great credit Mercedes-Benz Australia Pacific fought long and hard for this advanced technology to be brought to us. This involved considerable underbonnet rearrangement of the hybrid components so wouldn’t have been a cheap exercise.
By far the most important feature of any hybrid car is regenerative braking. Energy that is normally turned into heat and brake dust when you slow down is converted into electricity and stored in a battery until required for extra power. This take some of the load off the diesel or petrol engine, reducing its emissions and consumption.
As well as getting help by way of assistance from the electric motor, the Mercedes 2.1-litre turbo-diesel also has stop-start and ‘sailing’ functions. Sailing means the engine is turned off when it’s not required, such as when running downhill, or even cruising very gently under light-load conditions on level ground.
Stop-start, which is used in quite a few new cars nowadays, simply turns the engine off when the car is stationary, such as at traffic lights.
We did two long slow stages of our driving of the Mercedes-Benz hybrid through heavy city traffic in the Melbourne CBD. These are the conditions in which hybrids come into their own, because they are not only spending a lot of time stationary, but gain performance off the line from the big-torque electric motor.
We were most impressed that the fuel consumption of the big Merc sedan in city driving was a mere 6.0 litres per hundred kilometres on our first run, and 6.2 litres on the second one. A standard petrol car of this size could have tripled that consumption without really trying. Three times the emissions means tripling the exhaust emissions – and exhaust emissions are the last thing you want in canyon-like city streets.
On the open road sections of our drive program, from Melbourne airport out to Healesville and back by way of circuitous routes the Mercedes E 300 hybrid used between 5.5 and 6.5 litres per hundred kilometres. Thus our city performance was pretty much the same as in country running. That’s impressive.
All of these fuel numbers are considerably higher than the officially measured figures, which show Mercedes using just 4.3 litres per hundred kilometres. Hybrids are notoriously ultra-efficient on driving cycles but fail to meet them in real world driving. Sadly this Mercedes is no exception.
It’s time for the authorities to examine these unrealistic results and come up with a more practical test program, otherwise the public is going to lose faith in the measurements displayed on windscreen stickers.
What’s the Mercedes-Benz E 300 hybrid like to drive? The only real difference is that when you push the start-stop button the diesel engine doesn’t start. Instead you get a green light on the dash to tell you the system is ‘Ready’. The first few dozen metres of driving is normally done under electric drive alone, then the turbo-diesel kicks in.
Up to one kilometre at very slow speeds is possible from a fully charged battery. This is particularly useful if you’re in an underground carpark such as in offices or shopping centres.
Once the Mercedes E 300 hybrid is up and running we would defy you to notice any difference unless you looked down at the dashboard to witness the special display that tells you what’s happening under the bonnet. There’s a plethora of information: electric drive only; electric and diesel; whether the battery is supplying power, or being charged by the engine or brakes; and, as they say on the TV, much more.
Who will buy a Mercedes-Benz E 300 hybrid? Our feeling is that most will be early adopters and those who really want to make a statement about their care for the air we breath. Others may jibe at having to pay an additional $10,000 over the standard diesel E-Class when the fuel saving is likely to be in the range of just half-a-litre to one litre each hundred kilometres compared to a high-efficiency Mercedes E-Class CDI diesel.
What we really need to get people into low emission vehicles are concessions by the Australian government. There are many ways of providing these: reduced sales tax and/or registration; driving or parking benefits – or all of the above. The luxury car tax (LCT) is discriminatory because it pushes up the prices of some of the cleanest and safest cars on the market.
If really low emitting cars were allowed in transit lanes as happens in other countries that too would make it worthwhile for many to buy them.