'Theories about overall performance and potential average speed have to be looked at in a completely new light': The Aston Martin DB4

The luxurious two/four-seater Aston Martin DB4 represents the logical climax of the many years of sports and Grand Prix racing carried out by the makers. Their intention has obviously been to produce a car that would combine the comfort and convenience of a grand touring saloon with the qualities and performance normally associated with a racing car. There are no features of the design that can be described as revolutionary, but its cohesiveness is based on the hard experiences of international racing.

The remarkable power output of 240 b.h.p. is obtained at 5,500 r.p.m. from the six-cylinder twin-overhead-camshaft engine, which is of light-alloy construction. A most rigid crankcase is employed, and there is a seven-bearing crankshaft. The bore and stroke are both 92 mm, to give a total capacity of 3,670cc. The compression ratio is not unduly high at 8.25 to 1. Two S.U. carburettors are fitted; on the engine of equivalent capacity used for the shorter Gran Turismo and for sports-car racing, three twin-choke Webers are used. The sump has the large capacity of 17 pints, and a full-flow Purolator filter is incorporated in the lubrication system.

Though the engine is at its best on the highest-octane fuel, it will run happily on any premium-grade petrol. On many modern cars the engine compartment is largely filled with extras, but, with the Aston Martin, when one opens the forward-hinged bonnet, little else is revealed but essential mechanism, and accessibility is good. The gearing is such that an engine speed of 5,300rpm gives a cruising speed of 120 mph. The engine is fitted with chrome-vanadium wet cylinder liners.

Front suspension is by coil springs and transverse wishbones, and large telescopic hydraulic dampers are incorporated. The suspension at the rear is by coil springs, trailing arms and piston-type dampers. The rear axle is located transversely by Watt's linkage.

Rack-and-pinion steering is used and exceptional care has been taken to eliminate friction and wasted effort by the driver. The steering requires only 2½ turns from lock to lock, and just over 32 feet is required to turn the car.

The four-speed gearbox has a remote control of sports-car type, but synchromesh is provided on all four gears. As one would anticipate on such a fast car, Dunlop disc brakes are fitted, and a vacuum servo is incorporated in the hydraulic system to prevent the pedal pressure from being too high because of the fade-resistant linings used.

The car's fuel tank has the sensible capacity of 19 gallons, which, with an average consumption of 17 mpg, gives a range of over 300 miles, even allowing a gallon for fuel-gauge inaccuracy; in fact, there is a controlled reserve of three gallons.

The body can almost be described as integral with the chassis, as a framework of steel tubing on the Superleggera principle is connected to the chassis and covered with aluminium panelling. Apart from the principle of construction used, the lines of the DB4 owe much to Latin artistry. The air entry on top of the bonnet is not entirely necessary to feed air to the carburettors, but, as it fits over the leading edges of the overhead camshafts, it allows a lower general bonnet line to be achieved.

Most owners of such a car will doubtless regard it as a two-seater, as its performance almost demands the modern long-arm driving position, with the seat set well back, which reduces knee-room in the rear to a great extent. The interior of the car is most luxuriously fitted, and the equipment includes two bucket seats of Reutter type, on which it is possible to adjust the rake of the squab instantaneously and while in motion. Both front seats are well shaped to resist lateral force, and the driving position approaches perfection because of the well-placed pedal controls and gear lever. A valuable detail is that it is possible to transfer the right foot from the full-throttle position to the brake without having to move one's heel from the floor.

Despite the car's clean and sweeping lines, skill has allowed a large luggage boot to be provided, and the rear seat can be used to increase the luggage accommodation. A complicated system of levers controls the heating system, but once understood it works remarkably well. The fascia and instruments are well laid out, with materials that prevent any danger of irritating reflections appearing in the wraparound windscreen. With the large doors fully open entry is very easy, but some effort is required to get out with any degree of decorum.

As the induction system is not pre-heated, it is necessary to warm up the engine before expecting it to pull cleanly after it is first started up; a radiator blind is fitted to make this more rapid. There is no danger of being caught napping by the great power of the engine; it is so apparent that even the most careless driver could not inadvertently give too much throttle. In town driving it is best to make full use of the gearbox and, in fact, to ignore top gear and use the silent-running third gear instead.

While I would not suggest that the DB4 is in any way intractable, even its most enthusiastic user would not suggest that it is the perfect car for everyday town use. It is meant for use on the open road, where it comes into its own. Its makers have advertised — and the performance can be repeated at any time — that it can be accelerated from 0 to 100 mph and braked back to 0 in under 30 seconds. This is a truly remarkable performance.

Theories about overall performance and potential average speed have to be looked at in a completely new light when one is considering a car capable of 50, 75, 105 and almost 140 mph. on the four gears. The ease and accuracy with which the race-bred Aston Martin can be handled makes all normal cars appear clumsy and sloppy, and, although the suspension has clearly been set with high-speed stability and perfect adhesion in mind, it is interesting to note that it can be most favourably compared with softly suspended touring cars built for comfort only.

The car is not as silent as one might expect, but this is a small price to pay for such outstanding performance, and what noise there is is indicative of mechanical efficiency. The overall efficiency of the engine is shown by the similarity of the times required to accelerate through widely varying brackets of speed in top gear. Even without using the gearbox it is possible to leap ahead of other traffic with the greatest ease, and, what is perhaps more important, without ever feeling that one is driving in an exceptional manner.

On suitable roads previous conceptions about cruising speeds can be ignored and anything between 100 and 120 mph can be accepted as reasonable. The car is equally at home on a wide variety of road surfaces, and corners can be taken at high speeds in safety and easy comfort. On everyday roads one probably tends to take corners more slowly with the Aston Martin than one might with a slower car; the dazzling acceleration out of corners soon whirls the speedometer needle back to the selected cruising speed. Because of the reflection-free instrument lighting, the excellent headlamps and the comfortable and secure seating, night driving is especially pleasant.

It was not possible in the time at my disposal to find an opportunity to check the car's maximum speed with accurate timing, but there is no doubt in my mind that the claim of 140mph is justified completely. Apart from my feeling that a car of this price and quality would be better were it more silent, my only criticism applied to the gear lever. While excellently placed, its movements were rather lumpy, and it was essential to depress the clutch fully on every occasion if a clean gear change was to be obtained. It was interesting to note that with the engine switched off, the vacuum servo thus being made inoperative, greater pedal pressure could keep the brakes effective.

Combining almost racing-car performance with the standard of comfort associated with a town carriage, the Aston Martin DB4 represents truly first-class travel. It must be close to the ideal for the motorist anxious to travel far and fast without strain or fatigue.