When the single pale primrose DB4 was launched at the Paris Salon in October 1958, Marcel Blondeau, the French distributor for Aston Martin approached John Wyer on the stand with tears in his eyes "This is not a car, it is a folly, but I can sell as many as you can supply."
With a top speed of 140 mph, it was one of the fastest four seaters in the world and was on a par with the best of Italian Grand Turismos. Not wholly surprising, given the decision to have this distillation of years of Feltham ideas designed by Touring of Milan using their “Superleggera” system. The body consisted entirely of aluminium mounted on a trellis of small diameter steel tubes welded together. Body panels were attached to the trellis and clinched around angle plates which were welded to the members with graphite pads.
Items like windscreen, rear window frames an angle sections for the door hinges were attached directly to the frame. The design delivered slim proportions and outstanding all-round visibility. With the body mounted on a platform chassis, the seats could be set low without resorting to deep sills. The doors, which undercut the windscreen, were wide with frameless windows – no quarter lights – and the rear windows opened hingeing on their forward edges. Easier access to the rear with its new full width rear seat, past hinged and adjustable front seats from Reutter.
The wide parcel shelf concealed the presence of a 19 gallon petrol tank while at the back of the car, the boot lid opened to floor level. The battery, with its own master switch was behind a panel in the right hand wing and the spare wheel was in a separate contained under the boot floor.
Power came from the all new Tadek Marek twin overhead cam aluminium engine that weighed in 22Kg less than its predecessor. The twin cam shafts operated the valves directly through inverted steel tappets while those valves were splayed at an 80 degree angle – the seats all had inserts and the exhaust guides were all in direct contact with cooling water.
The block followed the contour of the liners which combined to save weight and strengthen the structure. The crankshaft was a nitirided steel forging which ran in seven bronze bearings – the connecting rods were polished and weight graded while the pistons each had two compression rings, the top one being chrome faced. Driving through a four speed, all synchromesh gearbox and a 10 inch single, dry plate Borg and Beck clutch – the engine was quoted as developing 240 bhp, although this was, in truth, probably nearer 208 bhp. Marek had, at John Wyer’s suggestion, researched horsepower claims on American engines and had found a mean discrepancy of 32 per cent – John Wyer’s reaction was "We can’t lie that much, we can only lie 15 per cent".
Ride and handling came courtesy of Harold Beach designed coil and wishbone front suspension and a rear set up of trailing arm and coil spring incorporating a Watts linkage. The brakes were all wound discs from Dun