Original is best – except where it can be made better. Laurence Meredith meets an owner who is not afraid to modify a motoring icon.
When Daimler-Benz’s legendary 300SL coupe was first unveiled to the New York public in January 1954, it caused a clearly audible sensation, for this was the first post-war supercar, with all that entailed. Based on the team cars that were victorious at Le Mans in 1952 the ‘Gullwing’, as it was instantly dubbed, was a racing car for the road and a very much prettier one than the purely functional racing cars which inspired it.
Capable of 150mph with the optional high-ratio rear axle, this was a fantasy car in a dreary, mundane world still recovering from war. It was also the world’s first production car to be fitted with direct fuel-injection, the 3-litre in-line six developing 250bhp (SAE) at 6200rpm. Such figures are commonplace today, but its worth remembering that 40 years ago an average saloon boasted around 40bhp and struggled to break 65mph.
Inevitably, the coupe was an inherently compromised design and there were drawbacks to running one as an everyday road car. First, the purchase price ($6820 in 1954) and running costs were exorbitant — not that this unduly worried the 1400 customers who bought Gullwings — but there were concerns about the car’s safety. Extricating yourself from an inverted coupe was virtually impossible because the doors couldn’t be opened in that position, and with its high-pivot swing-axle rear suspension the tail end was susceptible to sudden break-away during high speed cornering.
And then there was the old problem of the high sills; women in short skirts found it difficult to retain their feminine dignity while getting in and out of the cabin — not that their menfolk ever complained, of course, — and Daimler-Benz took notice that women were now among their customers.
So, after a production run of just two years, Mercedes answered the critics (and demands from the West Coast US dealers) by replacing the coupe with the 300SL Roadster, a more civilised road machine which, with its conventional front hinged doors and choice of soft or hard-tops, was designed to appeal to a much wider audience, including women.
Although similar in appearance to the coupe, the Roadster was substantially revised. The Gullwing’s engine was retained but, because the Roadster was 90kg (200lb) heavier than its predecessor, the special ‘competition’ camshaft offered as an extra-cost option on the Gullwing was fitted as standard in the revised car. The compression ratio was also raised from 8.6:1 to 9.5.1, but despite these modifications, the Roadster’s top speed was well down. Originally, five different axle ratios were available, but top speed never exceeded 130mph in road-going guise thanks to inferior ‘ragtop’ aerodynamics and the extra weight incurred through chassis strengthening changes. The Gullwing’s amazingly complex multi-tube spaceframe chassis was made for maximum torsional rigidity, virtually every tube constituting one side of a triangle. Loads and stresses imposed upon the structure result, therefore, either in tension or compression, but not in bending. At 82kg (181lb) it was also commendably light, but without the benefit of a roof structure the Roadster’s rigidity was wanting, which is why the frame was substantially strengthened, modified and lowered along the flanks, the lower sills allowing conventional doors.
Because of handling problems with the Gullwing, which incidentally, rarely bothered skilled drivers, the Roadster’s rear suspension was also revised, the high-pivot swing-axle arrangement being modified to a low-pivot type, which minimised the possibility of snap-out oversteer during high speed cornering.
The Roadster’s public debut was at the Geneva Motor Show in March 1957, and while purists, who by this time had become well and truly addicted to the Gullwing’s power, beauty and race-bred image, groaned about the Roadster’s comparative lack of ‘grunt’, it was the civilised and more user-friendly Roadster that everyone wanted to drive. Whereas the coupe had been an out-and-out sports machine, the softer Roadster was most definitely a Grand Tourer — better appointed, more luxurious and better equipped.
Between its debut in 1957 and demise in 1963, the car remained outwardly similar, the principal modifications being carried out under the skin in true German tradition. Changes between the Gullwing and Roadster were equally subtle, the most outwardly striking being the ‘Lichtenheit’, or headlamp units which, unlike those on the Gullwing, incorporated the indicator, headlamp, foglamp and parking light under one large lens (except on American-spec cars which more closely resembled the Gullwing).
Surprisingly, the Roadster acquired a pair of chromed ‘go-faster’ mouldings across the engine vents in the front wings, carried across onto the doors; these served no purpose other than decoration, which was a most unusual concept in functional Fifties Germany. One particularly useful change, however, was that the fuel filler neck was transferred from the inside of the boot to the outside of the left rear wing. (As an aside, it took Volkswagen another 10 years to catch on to this useful ‘tweak’.)
Major mechanical changes to the convertible included a long overdue swap from Al-fin drum brakes to all-round Dunlop discs from 1961. and a switch from cast-iron to aluminium-alloy for the engine block close to the end of production in an effort to shed weight. Interestingly, the new block was to much the same design as the old one, apart from the inclusion of the inevitable iron cylinder liners.
In all, 1858 Roadsters were sold worldwide, the majority finding customers in cash-rich America, and although no-one knows for certain, it is thought that around 80 per cent have survived. And, naturally, they remain as exclusive, expensive and desirable as ever. Why? Becaue the 300SL Roadster is significant A milestone. Almost a concept car. During the 1950s, true sportscars were the almost exclusive domain of British manufacturers; Jaguar. Austin-Healey and Triumph led the way in producing simple, loveable, inexpensive, fast and sometimes crude sporting machines, but it was Daimler-Benz who redefined the concept of a sporting car.
Although frighteningly complex, the 300SL would do everything you would expect of an XK140 and more; the main difference between the two was, and remains, that in the Mercedes you hardly noticed the performance. After the passage of nearly 40 years since the last Roadster rolled off the Sindelfingen assembly lines, the differences between inexpensive British sports cars and Daimler-Benz’s version of the same theme are actually more pronounced. The engineering quality of the 300SL is without rival, and it shows, several examples having achieved starship mileages without needing major surgery.
On The Road
My first impressions of engineer Ron Cushway’s pristine ivory-coloured 300SL, which he bought new for £4,600 in January 1963, were of a very modern car that hasn’t really dated. The looks are timeless, the graceful bodyshell a deliberate amalgamation of finely penned curves. At the front there are those imposing headlamps and the wide radiator grille — an amazingly complicated assembly in itself — with a massive three-pointed star forming a most conspicuous centrepiece.
And there’s the large bonnet with one ‘power bulge’ to clear the plenum chamber on the right of the engine, and the ‘fake’ on the left to balance the car’s aesthetics. Over each wheelarch are the famous ‘eyebrows’, which not only add to the businesslike look of this elegant masterpiece, but also separate the airflow along the upper and lower flanks to aid high-speed stability.
By contrast the meaty rump is rather plain, the boot lid simply adorned with a star and 300SL badge, the wings gently sloping to join the curvaceous valance. And below that massive bumper is the ‘fishtail’ exhaust pipe which, as I was soon to find out, exudes sonorous tones that are surely unique among motor cars.
Largely built by hand, some parts of the car-still bear evidence of old-fashioned craftsmanship; the underside of each bumper, for example, is pocked with hammer marks, and the headlining of the detachable hard-top remains as taut and perfectly padded as it was back in 1963 as fine an example of the upholsterer’s art as you’re likely to get.
Apart from having been treated to a high quality respray, 4 PK survives in its original, largely untouched form. Not impressed? Well, prepare for something of a shock. This car has covered no fewer than 380,000 miles — the engine oil is changed before every journey — a figure which is worth digesting for a bit. And particularly so because it still drives like a new car. Even the original boot lid and door locks still work perfectly, the doors open and close with a characteristic ‘thunk’, the shutlines are as precisely aligned as ever, the wheels with their steel centres and alloy rims show no signs of corrosion and, most telling of all, the deep red leather upholstery looks hardly worn. Quite unbelievable. Quite an eye-opener.
All Merc Roadsters are special, but this one differs from the rest in having some 92 Cushway implemented modifications; some, like the Mercedes-Benz badges on the front wings behind the wheelarches are neither here nor there, but important ones include ABS brakes. ABS brakes? On a 300SL? Yep. And those in the know in Stuttgart said it couldn’t be done.
Both the drum and disc-braked Roadsters stop perfectly well, but the fitting of an ABS by one of Ron’s friends in a similar car. The biggest problem was that the 300SL naturally hasn’t got a pick-up for the ABS speed sensor, so Cushway made one and fitted it to the rear of the propshaft. Originally intended for a W123 Merc, Cushway spent five months thinking about how he was going to tackle the job, and a day at Daimler-Benz’s technical training centre in Stuttgart taking measurements.
The loom runs down the right-hand side of the chassis with the computer control unit fitted above and in front of the passenger’s feet; the pump unit is located on the right-hand side above the front suspension, and, because of the compactness and complexity of the chassis frame, the whole system proved a tight fit all the way — there isn’t as much as 3mm of ‘free-play’ anywhere. And the system work too.
This unique car also has a non-standard central lubrication system, which Ron built and fitted himself to feed 23 separate points in the steering, suspension and chassis frame. Ordinary engine oil is used, the system being served by a separate tank bolted behind the right-hand front wheel and foot-operated by a pedal on the passenger’s kickplate’. There is even a drip feed for the clutch thrustrace bearing — the car’s only weak point apparently — and another which serves the handbrake lever, clutch and brake pedals. Other modifications include a small gauge which indicates how many hours the engine has run (I’m not sure why either), an electrical master switch fitted in the driver’s footwell, a central armrest and oddments bin between the seats, a manually-operated locking device to prevent reverse gear being selected by mistake — not difficult if you’re a bit clumsy when dropping from third to second — a CB radio for keeping in touch with other SL owners on international club rallies, and a bewildering host of other minor modifications.
And every available space in the car is packed with small leather-covered aluminium boxes neatly stuffed with tools and bits and pieces to cope with emergencies. In fact there are sufficient tools to completely rebuild the car at the side of the road, but, apart from one occasion when the cylinder head had to be removed in Germany to attend to a dropped inlet valve, they aren’t needed often.
From a driver’s point of view, everything from the cast-alloy flip-out door handles to the Gulliversize handbrake lever feels solidly ‘overengineered’, as if carved from a solid billet of lead. Getting into the lovely, snug-fitting seat is a little awkward on account of the broad sill and outsize steering wheel, which, unlike the Gullwing, has no tilting facility. The steering wheel, incidentally, is one of the few components which actually wore out, but, after careful refettling, the original is now back on the car and looking and feeling as good as new.
Naturally the large instruments are crystal clear and simply devised — a long-standing and laudable Mercedes policy — but were once slightly obscured by the full horn ring, which is why 4 PK now has a half ring — yet another modification. The dashboard is typical of the age in which it was conceived with a leather-clad top, painted metal middle section and a bottom bar also covered in leather. A most comfortable place to be, the luxuries and comfort of the cabin qualify the Roadster above all else as a GT rather than a sports car.
But it’s not particularly spacious — headroom is restricted with the hard-top in place — and the foot pedals, although nicely spaced, are slightly offset and do not line up with your body. As a result you sit slightly askew. But having owned a succession of German cars, this now feels natural to me. It shouldn’t, of course, but it does. Inevitably, all 300SLs were left-hand-drive — the cant of the engine makes a right-hand-drive conversion nigh on, but not completely, impossible — one or two examples have been converted in private hands.
Blip the throttle and it is immediately apparent that the 3-litre straight six is far from ordinary; it feels and sounds smooth and very powerful — a classic ‘throbber’ — and the clutch, although sufficiently heavy to cope with the demands of real brake horse power, is similarly smooth and self-possessed. Trundling along below 3000rpm,the big Merc is amazingly tractable; there’s no banging or spluttering, no sign that the plugs are going to oil up, yet if you wish you can leave it in top gear and accelerate all the way to 130mph from walking pace. But that’s not what SL ownership is about.
As the Gullwing’s straight-cut gears weren’t used in the Roadster, the all-synchromesh fourspeed ‘box is comparatively quiet. It’s absolute magic to stir the stick too. Changing up or down through the gate is a rare motoring experience, the slim lever slotting home in each ratio with absolute precision, needing just a light touch from the right fist. Build the revs slowly — there’s little to be gained from flooring the throttle except higher fuel bills — and the speed increases blindingly quickly; when the tacho needle bombs past 3000rpm, you’re left in no doubt at all as to what the 300SL is really all about.
The surge forward is elephantine, forceful, but never less than graceful. Never does the old girl lose her composure, unless you’re feeling brutal, in which case, the rear tyres — meaty Michelin radials — squeak as they scrub the road surface looking for bite, but the loss of traction is momentary and progress continues arrow-straight.
Curiously, this is the only supercar I’ve driven which failed to turn heads, which can either be attributed to the Merc’s timeless, inconspicuous styling (does it really look like a modern car?), or to the test drive being confined to the county of Essex. Whatever the reason, I’m sure it’s a great advantage.
So, what of cornering ability? Well, it’s really rather silly.
Despite its SL (Super Light) badge and alloy lids and doors, the Roadster is a heavy car — it’s difficult to imagine what Daimler-Benz’s idea of a heavy car is — and there are those swing axles to think about, or so I’m told. Enter high speed corner, keep the power on and. . . the great beast just sits there, its exhaust bellowing like an angry sergeant-major, confident and as flat as the proverbial pancake until you unwind the steering wheel. OK, it feels a little dated by today’s standards, a bit ungainly, and there’s a stubborn resistance to changing direction quickly but, in this respect, it compares well with its contemporaries.
Do what you like mid-way through a corner — lift off, bang the brakes on, press the throttle pedal to the floor, open a flask of coffee — and. . nothing happens. You’ve committed yourself to a line and there you stay. So on to the next corner. Increase speed, dip the anchor pedal, blip the throttle hard, boot it into third and turn in. Flick left — a hint of understeer — right — a slippery tail end at last — and left — no drama here — hit the accelerator — laughing water now in both eyes — and. . . a very excited, screaming, peaky six howls to your command up to the next twisty bit, which of course is never very far ahead in a Roadster.
Much has been said and written down the years about the supposed vagaries of swing-axle rear suspension, and a great deal of it — not all — is undoubtedly nonsense. When the driveshafts jack themselves up under exceptionally hard cornering, as they are apt to do, this serves as a warning that the limit has been reached; it is notice that you can’t pile on any more power, which makes the system inherently safe. And this occurs, I assure you, at speeds that are sufficiently high to offer even seasoned club racers the voltage they seek out on the track.
For those who lust after real excitement, a parachute jump from a 747 is probably sufficient for a buzz, but for classic car adrenalin fifties style, the Merc’s on-the-limit dynamics are the limit. As I wound my way through the bustle of the delightful Essex countryside, now fully in leaf after the most inhospitable motoring winter on record,it became obvious why SL owners hang on to their cars, for the 300SL Roadster is a true supercar. Really.
For sheer pace it’s not the equal of a Ferrari 250GT, and many would argue that the Italian car would beat the functional Stuttgart product in a beauty contest but, as an all-round driver’s car, and a reliable one at that, the Merc is peerless. SL owners also enjoy the huge advantage of a massive and comprehensive spares back-up service, not only from independent specialists, but from Daimler-Benz’s Oldtimer department in Stuttgart.
Smash a wing? You can replace it. Blow the engine into the middle of next week, and all the bits are available to rebuild it. Interior needs reupholstering — no problem. Paying for it? Tell your bank manager quietly over a glass of sherry on a Friday afternoon. Naturally, restoration costs are stratospherically expensive; the cost of replacing a fuel-injection pump for example — and the best way to ensure that you never need one is to use the car regularly — might send a twitch or two through the stiffest eyelids.
My time over with this car, its engine silent, hot air rising in spirals from the massive vents in the front wings, I sat on my old camera box for the purpose of gawping at the SL from a distance. It’s an impressive machine from any angle, a fat-cat that really knows it’s the best, the ultimate road-going GT from the classic post-war era, whose impact has perhaps only been matched since by the launch of Gordon Murray’s all-conquering BMW-powered F1 McLaren. The Merc has an awe-inspiring presence. But I wouldn’t want to own one. Why? Because my car-mad wife — She who can’t be ignored — would steal the ignition key and I’d never see either of them again. Now there’s a thought. Only joking, my dear. My thanks to Ron and Trudie Cushway for the SL and accompanying, impeccable hospitality.