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Five decades ago, the new W116 S-Class saloon raised the cult of Mercedes-Benz ownership into something akin to a religious order, reaffirming Stuttgart’s pre-eminence in the realm of large saloons.
There were faster saloons, quieter saloons and prettier saloons, but even those who struggled with the cold rationalism that underpinned this design found it difficult to fault.
Like it or not, there was no other four-door luxury car available in the 1970s that was so complete and so painstakingly engineered.
By then the 116-series was a nine-model family comprising carburetted and injected twin-cam straight-sixes, three flavours of single-cam-per-bank V8 and a five-cylinder turbodiesel (the latter for the USA only).
Work on the 1972 S-Class had begun in the mid-’60s, with the styling ‘frozen’ in 1969.
It was 2in longer and wider than the outgoing 108/9-series saloons, but sat an inch lower.
With its trademark double bumpers, rain-dispersing windscreen trims and large, dirt-resistant tail-lights, the shape had evolved under the guidance of the quietly masterful – and soon to retire – Friedrich Geiger.
It had a 5in-longer wheelbase than before, with the fuel tank behind the rear seats – rather than in the boot floor – for crash-resistance.
A more steeply raked windscreen and extensive safety engineering meant it was no roomier inside than the W108/109; tycoons looking to stretch out in the rear seats would have to wait until the introduction of the 450SEL of 1973, with its 4in wheelbase stretch.
The longer V116 shell was eventually made available with almost all of the engine options in the car’s home market – and in much of mainland Europe – but the British importer elected to keep the Lang exclusive to the 450.
Thanks to improved roll-over and side-impact protection, the new S-Class was a stronger but necessarily heavier car than the old model, by 225lb.
With its more rigid roof frame, pillars and reinforced doors, it not only exceeded the existing safety requirements but also any known pending legislation.
In 1978 the 116 would become the first Mercedes to be offered with anti-lock brakes, too.
Thoughtful details such as fully integrated front and rear seatbelts, a first-aid kit on the rear shelf and a warning triangle on the inside of the bootlid helped promote the idea that an S-Class was a very safe way to travel.
Mercedes preferred that its customers avoided hitting things and created a car it hoped would get you out of trouble, not into it.
Power steering was now standard across the range – connected to stability-enhancing zero-offset steering geometry and progressive anti-dive double-wishbone front suspension (developed on the C111 prototype), the latter featuring a single top link working an unusual, bulkhead-mounted anti-roll bar.
On the new 280 and 350 S-Class you could choose between a not-very-pleasant four-speed manual gearbox and an automatic – three-speed in the V8, four-speed in the 280S/SE, both with a conventional torque converter.
The automatic-only, long-wheelbase 450SEL joined the range in 1973 with a 4520cc version of the overhead-cam, iron-block V8 first seen in late American-market versions of the W108 saloon (badged 280SE 4.5) in 1971.
A 50lb ft higher torque value, peaking 1000rpm lower than the smaller 350SE V8, restored some of the performance lost to the heavier bodyshell.
To cope with this extra twist, the 450SE and SEL had an elaborate anti-squat system on the rear suspension not found on lesser models.
In Europe, the 450 was voted Car of the Year in 1974 and UK sales got properly under way in the midst of power cuts, 50mph speed limits and rocketing fuel prices.
Being neither light, high-geared nor particularly slippery, the W116 range was as thirsty as ever across the board (not even the crystal-ball gazers at Mercedes could have foreseen the fuel crisis of 1973), yet buyers seemed not to care, least of all in America where they couldn’t get enough of the German flagship as the Federalised 450SEL, fitted with giant ‘park bench’ bumpers.
In the UK it faced stiffer home-grown opposition, not least from Jaguar, whose XJ12 was not only faster and more refined (particularly in terms of ride and road-noise suppression), but also cheaper than even a basic 280SE.
Yet there was never any shortage of British S-Class customers, who cheerfully coughed up.
Frills on top were extra in lesser variants, but the UK concessionaire brought in 450SELs with the headlamp wash/wipe, electric windows all round, velour seats, central vacuum locks and rear head restraints – none of which was found on the 350SE.
A sunroof was a £250 option on the 450SEL, and you didn’t even get a rev counter!
Mercedes could have introduced the 450SEL 6.9 – the belated, W100-engined replacement for the 300SEL 6.3 – as early as the 1974 Geneva Salon but, post-fuel crisis, the time was not quite right politically, despite the fact that 400 eager customers had already put down deposits on whatever Daimler-Benz AG came up with to replace the much-lamented 6.3.
The public got its first sight of the exciting new 6.9 at the Frankfurt motor show in 1975.
Apart from a badge on the bootlid, and wider tyres, the 6.9 was visually identical to the 450SEL.
The 6.9, famously owned by James Hunt and a slew of other 1970s F1 drivers, was much more than just a 450SEL with a bigger engine.
It was more refined and easier to drive than the old car, but at least as fast and rewarding – thus satisfying former 6.3 customers (and hopefully attracting new ones), while at the same time meeting the demands of the power-sapping Federal emissions standards.
The M100 V8, fitted with a dry sump to sneak beneath the 116’s lower bonnet line, was bored out to 6834cc and produced 286bhp.
In the heftier 450SEL shell it didn’t have quite as much acceleration as the 6.3, but 0-60mph in 7.2 secs was still immensely fast for a car of this size.
Perhaps more importantly, the new 6.9 could cruise faster than the older car and handled much better.
It was probably of little more than academic interest that it had another 8-10mph of top speed in hand.
Rather than using airbags for its suspension, a more modern and reliable solution was achieved in the form of a hydropneumatic system, similar to Citroën’s set-up yet different enough to circumvent French patents.
The coil springs of lowlier models were replaced by gas-filled spheres connected by hoses to damper units.
The gas behaved like a progressive spring, becoming harder the more it was compressed, while the amount of oil in the system determined the ride height.
The 450SEL 6.9 cost the equivalent of £12,000 in Germany and $38,000 landed in New York with impact bumpers and a de-smogged engine.
In the UK, £10k separated the 6.9 from even the most expensive species of V12 Jaguar saloon.
With only 1839 cars built even in its best year (1979), the 450SEL 6.9 represented only a tiny fraction of total W116 production.
Today, collector interest is focused on the big-engined car – they have been hotly tipped since the day production ceased – yet I suspect that motoring writer Peter Grunert’s 1975 280SE is the rarer bird in the UK.
Showing low miles, lovely paint and a near-flawless cream MB-Tex interior, it might even be unique.
The late (1979) 350SE of Swansea-based Huw Francis, long-time Mercedes fancier and multiple owner, is similarly well preserved having had few keepers and little use – hence the near-unmarked blue velour interior, which is very rare to find these days.
Inside Anthony Dearing’s 450SEL 6.9, the dark-blue hide goes nicely with the silver paint.
You get zebrano wood, air conditioning, a small pull-out knob on the dashboard to control suspension height and an almost grudgingly compact rev counter, an instrument missing in both of the others.
Commanding views, firm seats, substantial and thick-rimmed steering wheels plus a formidable-sounding clunk from the doors are common to all three, but it’s surprising how tight rear legroom is in the standard-wheelbase cars.
The velour in the 350SE holds you best during cornering – all versions roll, but not to excess – and has a very particular and pleasing smell.
Equally, I like the cheerful practicality of the 280SE’s MB-Tex, while actively preferring the straight-grained wood on its dashboard.
The handsome twin-cam ‘six’ in the 280SE (the M110) looks approachable; the M116 V8 in the 350SE less so, although everything is easy to find in terms of getting to – and topping up – the fluids.
Yet there is something almost industrial about the mechanically injected, dry-sump M100 V8.
With its bulging cam boxes, giant battery and mysterious-looking suspension pump it fills the available space.
On the road, the smaller of the two V8s is sweeter, smoother and quieter than the thunderous 6.9, and naturally pulls shorter gearing so there is always acceleration on tap even at autobahn cruising speeds, which can’t do much for fuel consumption.
Interestingly, Motor got 13mpg from its 350SE, and Autocar extracted the same from its road-test 6.9.
At just 23.9mph per 1000rpm, the lower-revving 6.9 works on much the same principle.
But with virtually double the peak torque – produced at much lower revs – there is an urgency to the acceleration that still generates a thrill, no matter how many times you drive one of these cars.
The way the 6.9 slingshots down a motorway slip road and insinuates itself into – and then pulls away from – fast-moving traffic remains something to behold in a car this large, heavy and old.
Hold it in the 103mph intermediate gear or just let the transmission work things out itself; either way the nose lifts, the engine rumbles and you are where you wanted to be almost before you have had a chance to decide if it was really a good idea or not.
The cornering limits of the 280 and 350 are way beyond what you could safely discover on the road and both of these cars feel capable even now, the secret of their stability lying with that zero-offset geometry and large amounts of castor, plus three turns of the wheel between tight locks and plenty of steering feel.
Likewise the 6.9, except to say that large throttle movements should be treated with caution in anything but a straight line, and will certainly result in untidy fishtail slewing of a very ‘instant’ character if the road is damp.
The steel-sprung cars are set up to ride best at high speed, but they feel slightly ordinary and lumpy the rest of the time.
In contrast, the hydropneumatics of the 6.9 make the ride feel much more sophisticated and expensive – if slightly floaty on the sort of minor roads that tend, if anything, to highlight the relative agility of the more handy-feeling six-cylinder car with its lighter front end.
The ‘six’ seems more fleet of foot than the two V8s, turning in more eagerly.
If the brisk, pleasant 350SE goes easily as well as you think it should – and almost certainly better than you remember – the real surprise comes when you take the wheel of the ‘poverty’ 280SE.
With its throaty straight-six growl and aggressive mid-range pick-up, the silky twin-cam – which is good for 120mph – will wind up smoothly to three-figure cruising speeds in short order.
Your inclination is to use the gears because the M110 engine, with its peakier torque characteristics, makes the top-end acceleration seem comparatively more impressive than the low-end pick-up.
Boasting four speeds to the three found in the V8s’ transmissions, the secret to this impression is in the gearing and tuning of the upshift points.
With its chunky shifter and crisply gated action, the versatility and refinement of the gearchange was another area where the S-Class set standards in the ’70s.
So did the 500SE and SEL models of the W126 S-Class generation when it appeared, late in ’79, to replace the W116.
Lighter and more slippery, the new generation nevertheless perpetuated the philosophy – and much of the technical architecture – of the W116 into the 1980s.
Superbly developed in minute detail for wide acceptance in all markets, the legacy of these big 1970s Mercedes-Benz saloons is that they established the idea of the S-Class range as the international default-choice luxury saloon.
There were plenty of fast, handsome big cars to choose from in 1972, but few – if any – that were quite so accomplished in quite so many disciplines.
As actively and passively safe as the world’s best-equipped design and development team could make it, the W116 was a car to take the legislative challenges of the new decade in its stride – as well as setting a new benchmark for build quality and reliability.
Yes, they rusted away as quickly as almost anything else from the era, but that was something of an occupational hazard for a car designed for hard work rather than a pampered existence.
As the 450SEL 6.9 it became a legend, and deservedly so, but getting a representative set of W116s together proves, if nothing else, that all versions have something to offer.
Images: Luc Lacey
Luxury oil-burner: the 300SD
In 1977, a diesel version of the then five-year-old W116 S-Class, the 110mph 300SD, was announced in Frankfurt.
It was earmarked for export only to North America, complete with impact bumpers and quad circular headlights.
The magic ingredient was a turbocharger, making the 300SD the world’s first turbodiesel production vehicle when build began in April 1978.
The five-cylinder OM617.950 unit had an unmistakable diesel clatter about it at tickover, despite attempts to silence it with additional underbonnet sound-deadening, and was strengthened with sodium-filled valves, a tougher crank and a bigger, chain-driven oil pump.
The aim was to build a car with performance equal to a petrol 280S: with 110bhp at 4200rpm, 168Ib ft of torque and a 5000rpm redline, the diesel S-Class could get to 60mph in 12.7 secs with the 450SE’s higher 3.07 rear axle ratio.
Despite a 400Ib weight penalty it was 2.6 secs faster to 55mph than the W123 300D, and posted slightly better consumption figures than the smaller car: 25mpg in the city, 30mpg on the highway.
Inside, there was a 120mph speedo (in some states it only read to 85mph), an idle-speed adjustment knob on the dash and a glow-plug warning light.
The 300SD came only as an automatic and had an aluminium bonnet, bootlid and engine firewall to help keep it within the 4000lb weight class.
It was as much a response to new Federal legislation as it was to public demand.
In the wake of the 1973-’74 oil crisis, the US Congress had enacted the Corporate Average Fuel Economy (CAFE for short) standards in 1975, coming into effect in 1978.
This was measured as an average across the full range of models that each manufacturer sold on the American market.
The corporate average to be achieved in 1978 was set at 18mpg, but was due to rise incrementally to 27.5 by 1984.
Those who failed to meet these standards had to pay a fine of $5 per 10th of a mile per gallon over target, plus an additional ‘gas guzzler’ tax.
Priced at $25,000 on its launch, the enthusiastically received 300SD was not intended to be a poverty model: leather, a powered roof and climate control could boost the price considerably.
With 28,634 sold through to 1980, the model was enough of a hit to encourage its maker to build an S-Class diesel on the W126 platform, too.
The last-ever W116 produced in 1980 was an SD, a silver car now on display in the factory museum.
- Sold/number built 1972-’80/473,035
- Construction steel unitary
- Engine iron-block, alloy-head, dohc 2746cc ’six’ with twin Solex carbs or Bosch fuel injection; or iron-block, alloy-heads, sohc-per-bank 3499/4520/6834cc V8, with Bosch fuel injection
- Max power 158bhp @ 5500rpm to 286bhp @ 4250rpm
- Max torque 166lb ft @ 4000rpm to 405lb ft @ 3000rpm
- Transmission four-speed manual or three/four-speed automatic, RWD
- Suspension independent, at front by double wishbones rear semi-trailing arms; coil springs, telescopic dampers, anti-roll bar f/r (6.9 self-levelling hydropneumatic spring/damper units)
- Steering power-assisted recirculating ball
- Brakes vented front, solid rear discs, with servo and optional Bosch ABS post-’78
- Length 16ft 5½-9½in (4960-5118mm)
- Width 6ft 1½in (1867mm)
- Height 4ft 7½in (1410mm)
- Wheelbase 9ft 5-9in (2865-2972mm)
- Weight 3459-4060lb (1610-1842kg)
- 0-60mph 11.5-7.2 secs
- Top speed 118-145mph
- Mpg 13-25
- Price new £6995 (350SE)
- Price now £10-45,000*
*Price correct at date of original publication
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