From £70,4707
Luxury two-tonne S-class gets a diesel-electric hybrid system, offering a claimed 61.4mpg, but engine refinement issues dent its appeal

Our Verdict

Mercedes-Benz S-Class

The Mercedes-Benz S-Class, the self-proclaimed ‘best car in the world’, is back. Or is it?

Matt Burt
25 April 2014

What is it?

This is a diesel-electric hybrid version of the recently launched Mercedes-Benz S-class.

It utilises a 2.1-litre four-cylinder diesel engine and an electric motor, the latter of which is integrated into the car's seven-speed automatic transmission.

This, claims Mercedes, helps the two-tonne luxury saloon to average a staggering 61.4mpg while emitting just 120g/km of CO2. That means the Mercedes will cost you only £30 to tax, although for many buyers that will probably be somewhat of a moot point.

Performance is hardly lacking, with the rear-drive S-class reputed to be capable of 0-62mph in 7.6sec. Its top speed, should you find yourself on a suitable stretch of autobahn, is 149mph.

The hybrid is only offered in one trim, 'L AMG Line', and is priced at £72,260. That means it commands a premium of £1,555 over the conventional V6 diesel in an equivalent specification.

It is, however, £2445 cheaper than the petrol-engined S400 Hybrid – although that particular model is considerably more powerful.

What's it like?

While the S-class impresses on the numbers front, it falls down a little in the real world – primarily because of its four-cylinder diesel engine.

Because the Mercedes has such a refined and composed nature, it comes as somewhat as a surprise when you first hear the diesel engine fire into life.

It's not excessively noisy, even when worked hard, but it lacks the outright mechanical refinement of the six-cylinder diesel offered elsewhere in the range; it's not uncommon to feel a slight vibration through the steering column either.

By no means is it disappointing but it feels at odds with the Mercedes' luxury nature and takes the edge off that 'magic carpet' experience that you might otherwise expect.

The hybrid powertrain does function well, however. The diesel engine cuts in and out quickly and effectively and the electric motor grants the S-class silent low-speed cruising and coasting. The seven-speed transmission is equally competent, shifting through its ratios quietly and unobtrusively.

Charge from the hybrid's battery can be depleted quickly – even when parked, no doubt due to the Mercedes' substantial electrical and ancillary system – but it also replenishes at a sensible rate, meaning there's usually something in store when you need it.

There is, it must also be said, also something immensely satisfying about rolling along in absolute silence in electric mode – a feel-good factor that's enhanced by the fact that the S-class is capable of accelerating in a comparatively swift and eager fashion if needed.

During testing the car returned an indicated 34mpg, which while some way off the claimed average was good given the conditions – and still quite remarkable when considering the S-class' kerb weight.

At that rate of consumption a full tank of fuel would last for some 520 miles; average the claimed economy and the S-class will cover around 940 miles. Few, as a result, should have any range-related issues.

Otherwise, the usual Mercedes S-class qualities remain. It's easy to drive, supremely comfortable, lavishly equipped, impeccably well built and finished to a class-leading standard.

It may not be the most engaging luxury saloon available, but as a means of transport – even more so as a passenger – it's hard to beat.

Should I buy one?

Mercedes' hybrid S-class offers up impressive – and potentially attainable – economy figures but its four-cylinder diesel engine is not refined enough for a car of its calibre.

If the Mercedes instead had a six- or eight-cylinder diesel then it would deliver the blend of performance, economy and mechanical refinement that you might hope for.

Those seeking a comparatively frugal S-class should instead opt for the diesel S 350 BlueTEC. The smoothness of its V6 is much better suited to the car and it's still claimed to average a more-than-tolerable 50.4mpg. You may even find it as economical as the hybrid, depending on your usage.

Alternatively, if the unique abilities of a hybrid system appeal, you could buy for the similarly priced S 400 Hybrid L. It couples a serene petrol V6 with the same hybrid system, maintaining the S-class's tranquil luxury with ease.

Mercedes-Benz S 300 BlueTEC Hybrid L AMG Line

Price £72,260; 0-62mph 7.6sec; Top speed 149mph; Economy 61.4mpg; CO2 120g/km; Kerb weight 2035kg; Engine 4 cyls, 2143cc, turbocharged diesel, plus electric motor; Power 201bhp at 3800rpm, 27bhp electric; Torque 367lb ft at 1600-1800rpm, 192lb ft electric; Gearbox seven-speed automatic

Join the debate

Comments
26

25 April 2014
A LWB S-Class that costs £30 per year to tax! That's phenomenal, especially as it doesn't rely on being plugged in to achieve those impressive figures. It's not like it's slow either!

Looking forward to this same drivetrain in the new C-Class.

25 April 2014
Motormouths wrote:

A LWB S-Class that costs £30 per year to tax! That's phenomenal, especially as it doesn't rely on being plugged in to achieve those impressive figures. It's not like it's slow either!

Looking forward to this same drivetrain in the new C-Class.

That's all very well but, would be even better if the official EU test was more realistic, so this car might actually achieve the claimed consumption in normal driving.

 

I'm a disillusioned former Citroëniste.

25 April 2014
Motormouths wrote:

A LWB S-Class that costs £30 per year to tax! That's phenomenal, especially as it doesn't rely on being plugged in to achieve those impressive figures. It's not like it's slow either!

Looking forward to this same drivetrain in the new C-Class.

Do you really think that someone who buys an S Class really cares about car tax?

Are there really people who go out and think 'ooh I'd really love a diesel electric!'? These people aren't petrolheads.


25 April 2014
so a 40% tax bracket petrol head company director getting a s class for a company car is obviously going to get an S65 and pay £25k company car tax. he or she will totally ignore this blutech hybrid which only attracts £5k tax. not sure what world you live in, but in the one i know, a lot of people drive cars through work and non of them, not even the decent earners on six figure salaries would welcome paying 20k a year extra tax just so they can be a petrolhead. they would go for this or the 350 blutech through their company, and buy a second or third or "petrolhead" car privately for messing about in. if i remember correctly, most large luxury barges are fleet, not private purchases.

26 April 2014
Winston Churchill, not sure why you decided to call me an 'arsehole', but I've been called worse things by better people, so never mind.

As winniethewoo says, a huge proportion of S-Class registrations are accounted for by fleet sales rather than private purchases. With its very low emissions and impressive fuel consumption, of course this car is going to appeal hugely to them due to its staggeringly low running costs given its size. It's a no-brainer! The more powerful petrol S-Class' will sell in much smaller numbers, and mainly to private buyers who are willing to live with the comparably sky-high running costs.

Not sure what world you're living in.

26 April 2014
winniethewoo wrote:

so a 40% tax bracket petrol head company director getting a s class for a company car is obviously going to get an S65 and pay £25k company car tax. he or she will totally ignore this blutech hybrid which only attracts £5k tax. not sure what world you live in, but in the one i know, a lot of people drive cars through work and non of them, not even the decent earners on six figure salaries would welcome paying 20k a year extra tax just so they can be a petrolhead. they would go for this or the 350 blutech through their company, and buy a second or third or "petrolhead" car privately for messing about in. if i remember correctly, most large luxury barges are fleet, not private purchases.

Quite obviously MotorMoron was talking about car tax, not company car tax on two cars at opposite ends of the price spectrum. Of course company car tax is going to be more if you spend £100k more on the car. My point is that no one in their right mind will care about a couple of hundred quid on car tax i.e. that will almost never be the driving factor in decision making.


26 April 2014
winniethewoo wrote:

so a 40% tax bracket petrol head company director getting a s class for a company car is obviously going to get an S65 and pay £25k company car tax. he or she will totally ignore this blutech hybrid which only attracts £5k tax. not sure what world you live in, but in the one i know, a lot of people drive cars through work and non of them, not even the decent earners on six figure salaries would welcome paying 20k a year extra tax just so they can be a petrolhead. they would go for this or the 350 blutech through their company, and buy a second or third or "petrolhead" car privately for messing about in. if i remember correctly, most large luxury barges are fleet, not private purchases.

Well put, I am not quite sure why Mercedes chose AMG spec trim as I would have throughout a more comfort orientated option at a slightly lower price would be equally attractive to chauffeur fleet managers.

26 April 2014
......but!

The hybrid is less powerful, slower, heavier, only 10mpg more frugal and £1,500 more expensive.

End the thread. I win. There is no compelling case for this car.


26 April 2014
Winston Churchill wrote:

The hybrid is less powerful, slower, heavier, only 10mpg more frugal and £1,500 more expensive.

"Only 10mpg"? The difference is actually 13mpg, and that's a huge difference, especially in a car that is likely to appeal to high mileage drivers. The savings in tax make it even more appealing to fleets and company car drivers too.

The S350 BlueTEC is more refined, quicker and marginally cheaper. It's undeniably a crushingly capable car, and is likely to appeal to private S-Class buyers. But the S300 BlueTEC Hybrid's impressive fuel consumption and considerably lower emissions mean that it will be the one that will appeal to fleet customers.

26 April 2014
Motormouths wrote:

"Only 10mpg"? The difference is actually 13mpg, and that's a huge difference, especially in a car that is likely to appeal to high mileage drivers. The savings in tax make it even more appealing to fleets and company car drivers too.

The S350 BlueTEC is more refined, quicker and marginally cheaper. It's undeniably a crushingly capable car, and is likely to appeal to private S-Class buyers. But the S300 BlueTEC Hybrid's impressive fuel consumption and considerably lower emissions mean that it will be the one that will appeal to fleet customers.

I can see I'm not dealing with someone who has bothered to do the maths here so I'll try to be gentle with you.

The difference is precisely 11mpg between the two cars and the hybrid is exactly £6,355 more expensive.

Over 100,000 miles in 5 years the difference is fuel costs is £1,566.77 (@ diesel £1.366/l and petrol £1.295/l) in the hybrid's favour.

The car tax difference between the two over the same five years is £740 in the hybrid's favour.

Therefore, given the price difference, for a heavier, slower and less refined car, it costs you £4,048.23 more to run than the petrol.

Now, would you shut up?


Pages

Add your comment

Log in or register to post comments

Find an Autocar car review

Driven this week

  • Lexus LC500
    Car review
    20 October 2017
    Futuristic Lexus LC coupé mixes the latest technology with an old-school atmospheric V8
  • Maserati Levante S GranSport
    First Drive
    20 October 2017
    Get ready to trade in your diesels: Maserati’s luxury SUV finally gets the engine it’s always needed
  • Jaguar XF Sportbrake TDV6
    First Drive
    19 October 2017
    The handsome Jaguar XF Sportbrake exhibits all the hallmarks that makes the saloon great, and with the silky smooth diesel V6 makes it a compelling choice
  • Volkswagen T-Roc TDI
    First Drive
    19 October 2017
    Volkswagen's new compact crossover has the looks, the engineering and the build quality to be a resounding success, but not with this diesel engine
  • BMW M550i
    First Drive
    19 October 2017
    The all-paw M550i is a fast, effortless mile-muncher, but there's a reason why it won't be sold in the UK