Motor Sport

Road Impressions

Mercedes Benz 450SL

Most of the publicity which has been given to the 450 S-class range of cars which Mercedes-Benz announced last year to supplement the 350 S-class range has fallen upon the 450SEL luxury saloon because of its election as the Car of the Year. However, sharing the same 225 b.h.p. DIN, 4.5-litre V8 engine is the 450SL, one of the handful of the World’s luxury cars offering the opportunity for opentop motoring, the latest in the line of Mercedes SL sports cars which began with the famous 300SL twenty-two years ago. If we are all to be hounded by VASCAR, radar and television cameras (on the southern end of the M6) and the threat of disqualification for three trivial offences, then one of the few remaining motoring pleasures which Authority has yet to ban or tax is open-air motoring and the 450SL is one of the rare means of enjoying this in expensive style. The 350SL remains in production, but importation to the UK has ceased in favour of the 450SL.

If the 450SL’s lineage is traced back to the 300SL then Mercedes’ policy would seem retrograde to the enthusiast. That magnificent classic sports car had a 160 m.p.h. maximum speed and formidable acceleration even by modern standards. With a claimed maximum speed of 134 m.p.h. the 450SL is in fact the fastest two-seater production Mercedes since the 300SL—on two more cylinders and with an extra 1.1/2-litres. The 450SL is for a softer generation of Mercedes customers, bred on a diet of big, quiet, lazy engines, automatic gearboxes and power steering, all of which this latest sports car has as standard. It also has the same remarkably high standard of engineering which the 300SL and all other Mercedes have exhibited, but for an £8,598 car it is badly lacking in luxury equipment.

It would appear that Mercedes, suffering inflated prices in the UK because of the exchange rate, have kept the basic specification of the 450SL down to a minimum in order not to make the list price too frightening. Thus it is that the man who is regularly accustomed to paying over £8,000 for a motor car and so equally accustomed to creature comforts like electric windows, air-conditioning, stereo, will find that in the SL his £8,598 buys him nothing of the sort. By the time he has added the formidable array of “missing extras” his bill will have grown to well on the wrong side of £10,000. The listing of an occasional rear seat as a £104.96 extra in this two-seater car is unforgivable, while electric windows to replace the 5.3/4 turns (11.1/2 turns down and up) manual winders should be included too instead of costing £133 as an extra. Like BMW, Mercedes charge roughly twice the price of Jaguar for air-conditioning: £632.96 plus another £46.37 for tinted glass which is insisted upon with air-conditioning. The alloy wheels fitted to the test car may look attractive and elegant compared with the standard steel variety: the attraction costs an extra £378.35. I was amazed to find a terrific squealing from the inside wheel and a huge cloud of smoke in the mirror the first time I floored ‘the throttle to take an opportune gap in the traffic at a busy roundabout: this sophisticated chassis with anti-dive front and rear and starting torque compensation does not include a limited-slip differential, which is just now being re-introduced as a £64.21 extra after being dropped for a while for technical reasons. A factory-fitted Becker Mexico stereo radio with a mere manual aerial costs £313.97 or a Becker Europa mono £115.96. Alternatively, of course, the dealer can fit the radio of your choice, which in the case of the test car was a Blaupunkt Blue-Spot complete with an electric aerial.

Standard equipment does include the steel hardtop and a proper convertible hood which folds away manually beneath a hinged steel tonneau panel. Strong muscles are required for either conversion : that elegant hardtop is exceptionally heavy even for two strong men, while more than a lady’s delicate hand is required to twist the two taper-screw pegs locating both soft-top and hardtop in the top of the screen rail. Similar, but easily turned pegs locate the hardtop at the rear of the door (the soft-top hinges at the same point) and in both cases a single peg in the rear centre is pulled down, locked and released by a windowwinder type handle on the inside panel. Both the canvas hood and hardtop were perfect fits on the test car, though there were some minor rattles and groans from both.

Particularly disappointing was the amount of wind noise. I expected this from the soft-top but thought that Mercedes of all people, to whom wind tunnels are as much a part of car design as drawing boards, would have built a quiet hard-top. Adjustment of window pressure against the rubber door seals might have improved this on the test car. A louder and sometimes annoying wind howl transpired to be the tail-mounted radio aerial, no fault of the Mercedes factory. In common with its sister S-class cars, the SL shares the wind-tunneldesigned screen pillar gutters to deflect rain and dirt from the side-windows and light units which too deflect dirt.

Apart from its exclusivity, the beauty and elegance of design which give it that special “presence” in any company and its adaptability to suit the weather, the customer pays for ‘undisputed engineering excellence and safety—both active and passive. Active safety dictates good handling, road-holding and brakes, which is what we are all prepared to pay for in any case. Passive is the protection which the car affords to the occupant in the event of a crash and in this respect Mercedes are undisputed leaders.

The new 4.5-litre V8 engine, fitted with one overhead camshaft per bank, gains its additional litre by an increase in stroke from 65.8 to 85 mm., the bore remaining the same as the 3.5 at 92 mm. It is fitted with the same Bosch electronic fuel injection system and transistorised ignition as the smaller model, produces 25 b.h.p. more at 800 r.p.m. less (5,000 r.p.m.) and is claimed to produce 40 per cent more torque at low revs (peaking at 3,000 r.p.m.) and 20 per cent more at 5,000 r.p.m. than the short-stroke engine. The MercedesBenz three-speed automatic gearbox with torque converter has been strengthened to accommodate the increased torque which has enabled a 3.07 :1 final drive ratio in place of the 350’s 3.46 :1.

The electronic injection automatically compensates for temperature, so warm or cold starting was immediate and the engine showed no objection when driven from cold. Mercedes have solved the inherent V8 secondary balance problems so well that neither in feel nor sound is the arrangement of cylinders more than minimally perceptible. Engine noise is almost completely unobtrusive unless accelerating hard, the gearbox can be heard at low speeds and over rough surfaces there are some unanticipated thumps from the suspension and tyres. On the whole, though, this would be a very silent car were it not for wind noise, the level of which is little different whether hard or soft-top is in place. On the credit side, this wind noise seemed to reach its peak at around 80 m.p.h., so that at an indicated 140 m.p.h. with the Vdo tachometer needle just holding short of the ignition cut-out at 6,000 r.p.m. (150 r.p.m. beyond the start of the red line) noise was no more disturbing than at twofigure speeds. Maximum recommended speeds in the gears are 59 m.p.h. and 96 m.p.h. using the manual hold, automatic changes are very smooth, but up to about 20 m.p.h. in traffic the box can be indecisive as to which gear it prefers. The thick rubber golf-club shaped lever works in a gate on the centre console, the gate is considered foolproof enough not to require an over-ride button, but twice I hit neutral when selecting top from second when in a hurry.

Apart front the rear axle, the running gear on the 450SL is no different from the 350SL. Twin wishbones with an anti-dive control device, coil springs with progressively acting rubber helper springs, double-action shock-absorbers, and an anti-roll bar make up the front suspension. The rear suspension retains the diagonal swing axle but (and this feature is unique to the 450S series) is otherwise redesigned to incorporate anti-squat geometry and what is called “starting torque compensation”, all necessary to prevent the rear end dipping when the torque of the 4520 c.c. engine is put into effect. If the actual mechanics of this axle remain hazy then it only requires a test run in any of the 450S series to realise how incredibly effective it is. Under the harshest of acceleration, even with a load on board, the tail refuses to dip to upset passenger comfort. What is even more impressive is the almost uncanny effect this system (which also keeps rear wheel camber constant) has on braking. Its effect when the brakes are applied is to pull the tail down slightly which in conjunction with the anti-dive front geometry restricts weight transference. When the servoassisted, dual-circuit disc brakes are applied the car feels to glue itself down to the tarmac.

Mercedes’ own power steering with steering shock-absorbers is too light for my tastes, but has excellent feed back and response through a too-large, roughly sculptured, plastic-rim wheel mounted too high on a non-adjustable column. There is some roll when cornering hard, but the road-holding of the 205/70 VR 14 Michelin XWX tyres is outstanding and this powerful, automatic transmission sports car is not in the least “hairy” if used sensibly.

Criticisms which come to mind are the lack of a vanity mirror, the Acculux rechargeable torch in the lockable glove-locker had failed, the central hand-brake lever operating separate rear drums would hold only if pulled hard on to the last notch (left-hand-drive cars have a foot-operated handbrake), the cigarette lighter worked only if the ignition was fully on, not in the auxiliary position, the facia-light rheostat switch was awkward to reach behind the steering wheel and the gearbox was slow to take up drive in reverse.

Vdo instruments in the binnacle ahead of the driver are particularly clear: the large central 160 m.p.h. speedometer is given prominence, the tachometer is on the right and a separate gauge with oil pressure, water temperature and fuel gauge on the left. A Kienzle clock is in the centre of the facia. One steering column stalk controls two-speed plus intermittent wipers, flashers and headlamp dip and flash, a foot pedal controls the screen washer-wipe and, if the lights are on, automatically activates the standard washer-wipe system on the halogen headlamps. The boot is one of the roomiest of any sports car, the occasional seat (an extra, like the test car’s heated rear hardtop screen) folds down to form a luggage platform, the front seats have reclining back rests and incorporate head rests, but the driver’s seat needs a spanner to adjust the height and its leading edge dug into my thighs. An excellent heater warmed the doors and side windows too, but the handbook was in German !

This Teutonic two-seater averaged anywhere between 13 and 18 m.p.g. from its 19.8 gallon tank, depending upon exuberance and sells for £1 more than the 450SE saloon which offers a lot more car. – C.R.