THE WORLD'S FASTEST TOURING CAR

THE WORLD’S FASTEST TOURING CAR

5.4 LITRE SUPERCHARGED MERCEDES-BENZ ATTAINS 108 M.P.H. A ” JEKYLL AND HYDE” CAR. Wherever cars are used throughout the world, no symbol is better known or more respected than the simple, dignified

three-point star of Mercedes-Benz. In England the car is almost invariably known as the “Mere.,” and the term at once conjures up a picture of .a long, .low, car, with a sharply pointed radiator, and massive flexible exhaust pipes protruding through the sides of the bonnet.

For many sporting enthusiasts of all nationalities, a ” Mere.” represents the sum mum bonum, the answer to the question “what car would you buy if you had an unrestricted choice ? ” Mercedes-Benz, perhaps more than any other firm, have garnered the reputation and the experience which comes from a list of racing successes that goes back to the dawn of automobiles. The latest scion of the great German house is the 5.4-litre supercharged eightcylinder car, known as the Type 540K (K stands for hompressor, the German word for supercharger). This car was introduced at the last Olympia show, and is the successor to the 5-litre supercharged car. As a piece of engineering, it stands un

surpassed. It is amongst the most luxurious, as well as the fastest, cars in the world. One must, however, emphasise the fact that the 5.4-litre Mercedes-Benz is a luxury touring car, for use on the

ordinary roads. In its production the manufacturers have not attempted to introduce features suitable for racing, though one must remember that, touring car as it is, there are only one or two production cars, and those of super-sports, almost racing type, which can command as great a speed.

This point is important for since the days of the old ” SS K “—in its time quite the fastest production car in the world—the Alercedes-Benz company have slightly altered their policy. The ” SS K ” was a sports-car. It was also eminently suitable for fast touring but in its construction luxury features had not been developed, as on the 5.4-litre. Sonic of the old adherents of Mercedes-Benz, men who would never buy any other type, grieve sadly for their beloved old car, with its rather harsh springing and its sporting characteristics.

Cars must progress, however, and the 5.4-litre Mercedes has an appeal to a much wider range of motorists than to the sporting enthusiast alone. For the sporting man there is still that colossal speed, that soul-satisfying acceleration when the foot is pressed hard down and the blower, with its famous whine, comes into action. Yet the touring motorist has a car which is rock-steady at all speeds, and has suspension with which a jar is never felt even on rough surfaces. On the occasion of the present test of the 5.4-litre Mercedes-Benz, with cabriolet body, by MOTOR SPORT, two opinions of people who travelled in the car are worth quoting, to show its Jekyll

and Hyde qualities. One, a sporting enthusiast, said, ” This is a man’s car.” The other, a lady, said, ” This is a duchess’ car.”

It is perhaps unfair to the Mercedes to compare it at any time with Mr. Hyde for he was rather an unpleasant person.

He was fierce, however, and fierce is certainly the word to apply to the acceleration when the blower is put in four times on all the gears. The effect is almost shattering until one gets used to it, breeding such an exhilaration that one has to remember that even on a Mercedes there are rev. limits Keeping to a limit of 3,500 r.p.m., one can attain about 25 m.p.h. in first gear, close on 50 m.p.h. in second, 75 m.p.h. in third, and in top gear almost whatever the road conditions will allow l The car being a road machine, it was tested on the road, and, fantastic as it may seem, a speed of no less than 108 m.p.h. was attained on a long, straight, level stretch which is almost equal to

a German autobahn. One hundred miles per hour was also attained on another quite different, but shorter stretch. Readers of MbroR SPORT are not, one may assume, given to grandmotherly

inhibitions, but even they may be surprised at such speeds, with a suspicion that they might be dangerous. If such a suspicion crossed their minds, they have not had the good fortune to travel in a 5.4-litre Merckles. The all-independent suspension of all four wheels, the perfect steering, and the massive power of the brakes combine

to give absolute security. The driver must know what he is about, of course, but so far as the car is concerned he knows that it will do exactly what he expects it to do. If, for instance, he hits even quite a bad bump at 100 m.p.h., the car will not notice it. It will give a slight, dignified nod, and proceed firmly on its way. Did not Sir Henry Segrave predict, years ago, 200 m.p.h. travel on the roads in safety ? The Merades is a step along that road. The 5.4-litre Mercedes has a slightly different gearbox from its predecessor, the 5-litre. It has the same ” over-top ” arrangement, by which the highest gear is automatically engaged by moving the lever across and merely releasing the throttle ; the clutch is not used, and the

gear may be “pre-selected.” On the 5.4-litre, however, the direct drive is on the highest gear, whereas formerly it was on third gear. The changes from first to second and second to third (of semi-synchro-mesh type) are made in the normal manner, and are now much easier to effect. Particularly at the slower speeds, the gear change is indeed simple. But when one is letting loose 180 b.h.p. (which is the horse power developed when the supercharger is used), and is gathering speed

with such rapidity, one naturally needs experience of so mighty a car before getting the best out of acceleration figures. In one single, glorious day’s rim, the driver on the present occasion did not feel that he wes able to do justice to the figures which follow. A driver

who knew the individualities of the gearbox thoroughly would certainly have improved some of the figures considerably, for no attempt was made to ” trash the gears.” Vet such figures, from one familiar with high speed, but not with this par

The imposing front view of the 4-seater Mercedes Benz, cabriolet body.

ticular gearbox, are interesting, as showing what one could do right from the start. And what a start I In with the blower. The wheels spin. A banshee wail arises. From a standstill to 30 m.p.h.

in 3.9 secs., 40 m.p.h. in 6.7 secs., 50 m.p.h. in 8.5 sees.

We have already got into second gear without wasting much time, but now we change to third. One must not slip the clutch on the blower, it must be in or out. Off comes the foot, a sudden silence. A slight pause, and in goes third. Down with the throttle pedal, down further to bring in the blower once more. Again that inspiring whine rises and rises. 0-60 m.p.h. in 13 sees. Our unskilled change has spoilt that figure. Now we really are moving. Seventy miles per hour in 1:3.9 secs., 80 m.p.h. in 21.5 secs. Now we’re in top ! Ninety miles per hour in 37 secs. 1 One hundred miles per hour. One hundred miles per hour in 41.5

secs. I We slow up, feeling rather shaken—mentally, not physically. One of the reasons that the car is so steady on the road is because of its solid build. Actually it weighs 21 tons, which is no mean mass to get moving from a standstill. The gears, too, are high, to give an easy cruising speed. At 100 m.p.h. the engine is turning over at

approximately 3,000 r.p.m. On many Ordinary cars, this engine speed would represent only 45 m.p.h. I The Merce’des gear ratios are 11.9 to 1, first ; 7 to 1, second ; 4.4 to 1, third ; 3.08 to 1, top. Mr. Hyde has had his fling, but has had the advantage of the wonderful springing and steering, not to mention the Lockheed servo brakes. Perhaps Dr. Jekyll Will not use the blower So much. He will find the 5.4 litre, with its bigger engine, very much more responsive than the previous version of this car, if he has tried both. Even without the blower, there is a tremendous surge of

power. There is no purpose in giving acceleration figures without the blower, for the whole purpose Of the Merckles supercharger application is to give good acceleration when it is wanted. Alternatively, one can attain a high speed quickly, and then release the supercharger and maintain that speed with little diminution. The Mercedes supercharger, of Roots type, blows through the carburetter, instead of drawing from it, as with most supercharged cars, and the well known whine is caused not by the dutch which brings the blower into action when the foot is pressed hard down, or by the gears, as some have quite erroneously supposed,

but by the air rushing at high speed into the blower intake.

The “SS K” also had this system of supercharging, but the method of fuel feed was vastly improved on the new model. A special mechanically-driven pump delivers the fuel at 14 lb. pressure to the carburetter when the blower is working, and since the blower pressure is 10 lb. to the sq. in., there is no risk of fuel starvation. The ” SS K” had a somewhat complicated system of balance pipes to equalise the pressure.

The rear tank holds 24 gallons, and there is also a separate reserve tank under the dash which holds just over 2 gallons, and feeds by gravity. The petrol consumption is about 10 to 12 m.p.g. Dr. Jekyll will also appreciate the beautiful finish of the coachwork, the softness of the upholstery, and the way that the backs of the front seats fold down to form a couch if desired. There are two large fitted suitcases in the rear luggage boot. There are two horns, with a deep and melodious note, and either one or two may be used by

means of a two-way switch. A fog lamp is also fitted, and self-cancelling direction indicators. Dr. Jekyll will be just as satisfied as

Mr. Hyde. The Mercedes-Benz is a two-purpose car. It can “coo as gently as any sucking dove,” or roar like :any lion.