What is it?
With the S 300 BlueTEC Hybrid, a four-cylinder diesel engine is being offered to S-class buyers in the UK for the first time. The 2.1-litre four-cylinder diesel engine in the new model was offered in the S 250 in the previous-gen S-class, a car that never made it to these shores.
Now it’s back in the new line-up, armed with hybrid assistance, to produce some deeply impressive numbers, and a place on UK price lists.
The CO2 figure of 115g/km and combined fuel economy of 64.2mpg seem almost implausibly low for a car of the S-class’s size and weight and more akin to that of an efficient family hatchback; but the boffins at Mercedes reckon a real-world figure of even 70mpg might be possible — should you have the most feather-like of right foots. Crikey.
What's it like?
Sadly, it’s better on paper than it is in reality. While those figures are deeply impressive and achievable, you have to remember this is a luxury car. And the powertrain just doesn’t have that ludicrously high level of polish and refinement you automatically associate with the S-class.
Not that it’s particularly noisy; yes, there is a grumble in the background that is absent in six-and eight-cylinder S-classes, but the cabin is well insulated and helps mask the sound. It can’t mask the vibrations into the cabin though that the powertrain produces; feeling any vibration into the cabin from the powertrain is an alien concept in an S-class.
Performance is strong enough, and it’s possible to creep along on electric power alone at low speeds and when backing off the throttle at mid-range speeds. And the fine ride quality and interior comfort, such famous S-class traits, are not lost in its transformation into fuel sipper.
Should I buy one?
This powertrain is a case of downsizing being stretched a little too far. It’s far from being a bad car, it’s just not the powertrain we’d want our S-class served up with.
For the same expected price —when the model arrives in the first quarter of 2014 at around £65,000 — you will be into S 350 BlueTEC territory, with its vastly more refined and hardly inefficient powertrain.