Introduced at the 1965 Frankfurt Motor Show, in what became a Mercedes-Benz trend, the W108 series Mercedes-Benz raised the bar in terms of mass-production luxury saloons – not only in-house but for the motor industry in general. Such was the quality that many are still on the road today, and firm favourites in the practical classics race.

The W108 was essentially an upgrade of the distinctive W111 ‘fintail’ Mercedes, and design of the new model began in 1961 under the leadership of Paul Bracq, who was the company’s head of design from 1957 to 1967. Visibly, the W108 had a lower waistline that helped increase the glasshouse (the windscreen alone was 17% bigger), a 60mm lower ride height and 15mm wider doors. And whereas the W111 had subtle ‘Heckflosse’ on the rear fenders as a styling feature, the W108 boasted vertically stacked dual quartz-halogen headlights as its distinctive characteristic. The distinguishing Mercedes grille began its steady transition from the long-running narrow, tall shape into one that was lower and wider.

The initial model line-up consisted of a 250S, 250SE and 300SE, as well as a single W109 series, 115mm longer wheelbase 300SEL, which heralded all future S-Class models having an LWB derivative. In November 1967, the three W108 models were replaced with the 280S and 280SE and were known as the ‘stroke 8’ models – identified on the body plate as ‘/8’. Both were powered by the M130 2778cc six-cylinder single overhead-cam engine. However, the 280S was fuelled by two twin-barrel Zenith carburettors, and with a 9.0:1 compression ratio developed 103kW at 4200rpm and 223Nm of torque at 3600, whereas the SE boasted Bosch mechanical fuel injection. Running a 9.5:1 compression ratio, the injected motor, which incorporated temperature and altitude compensation, produced 118kW at 5500rpm and 240Nm at 4250. Molybdenum-coated piston rings were used for extra reliability and longer service.

The standard transmission for Europe was a four-speed manual with the option of a four-speed automatic that was developed and built in-house – unusual for a mainstream European manufacturer of the time. Taking into account such factors as weight and gearing, the power and torque differences gave the 280S a top speed of 185km/h and the 280SE 193km/h, but for both models the 0-100km/h time was around 10.5 seconds. Claimed overall fuel economy was given as 10.5 litres/100km.

While many engineering principles were carried over from previous models, the W108’s suspension system incorporated a reinforced low-pivot swing axle with a hydropneumatic compensating spring at the back, and double wishbones, coil springs and a stabiliser bar up front. Dual hydraulic power-assisted disc brakes with anti-dive control were fitted all round, and wheels were 14-inch x 6J shod with 185HR tyres. Recirculating ball steering was offered with or without servo assistance. With an overall length of 4.9 metres and a wheelbase of 2.75 metres, the turning circle was a relatively modest 10.8 metres.

The W108 arrived in South Africa in late 1968, by which time the model range had been enlarged with the addition of 220, 220D and 230 derivatives. At a time when the automotive world was reeling from Ralph Nader’s book Unsafe at Any Speed (published in November 1965), which highlighted “designed-in dangers of the American automobile”, Mercedes-Benz was already well into safety research and the W108’s body shell had a very rigid passenger compartment, with front and rear sections designed as crumple zones in the event of an accident. Inside, the energy-absorbing facia held controls and switches and the steering column was telescopic, with an impact damper mounted under the steering wheel. Three-point seatbelts for the front seats were already established.

Although many critics described the car as a ‘fintail without the fintails’, the vehicle was an amazing success. Throughout the W108’s production life from 1965 to 1972, when a total of 359 522 were built, the 280SE was second only to the 280S in sales – 91 051 versus 93 666. The car’s simple and square contours provided ample engine, passenger and boot space and the design has a timeless quality. But the W108 is perhaps better known for its reliability and durability, as proof of excellent and long-lasting Mercedes-Benz engineering.