The Grand Prix teams' favourite race in the 1930s was a race which did not even count towards the European championship: the Tripoli Grand Prix in Libya, an Italian province since January 1934. Its governor was bearded air marshal Italo Balbo, addicted to motor racing and other good things in life - and a brilliant host to boot.
The Tripoli Grand Prix simply was an attractive proposition for the teams. They were greeted by summer heat while Europe was still shivering with cold, an exotic ambience on white marble terraces and under palms, glittering parties and generous prize money, not least because Italy had been indulging in betting on place and win within the framework of a lottery since 1933. Small wonder, therefore, that the Grand Prix circus liked to come to Tripoli.
But in secret the organisers were quite annoyed that the last victory of an Italian racing car, an Alfa Romeo, dated back to 1934. Ever since, the Silver Arrows had been virtually subscribed to first places on the fast, 13-kilometre Mellaha racetrack, round the eponymous lake outside the city gates of Tripoli. The 1935 was won by Rudolf Caracciola. In 1937 and 1938 it was Hermann Lang's turn driving the Mercedes-Benz racing car. In 1936 the winner had been an Auto Union racing car.
That nuisance had to be remedied. In 1937 and 1938 there had already been a separate 1.5-liter category to ensure Italian triumphs, at least in the lower echelons. Rumour had it that the Grand Prix formula from 1941 onwards might be for cars with the same displacement. To be suitably ahead of things but also to put a stop to the perennial German victories, the Italian motor sport authorities decreed a 1500 cc limit (voiturette formula) for their own open-wheel cars from 1939. Alfa Romeo with their Alfetta 158 and Maserati with their new 4CL were well prepared for this.
The new regulations were announced in September 1938.
Mercedes-Benz racing manager Alfred Neubauer was informed about this after the Gran Premio d'Italia in Monza on 11 September 1938. The 13th Tripoli Grand Prix was to take place on 7 May 1939. So there were less than eight months to come up with a new car - a race against time. It was, however, to end in outstanding triumph.
A first meeting of the men involved was scheduled on 15 September 1938. Max Sailer, ex-racer and chief engineer since 1934, shrugged off the objections raised by the design engineers that such a project was impossible to realise in view of the scant time. It had to be. On 18 November followed the official order by the management. By mid-February 1939 all the essential drawings by engine specialist Albert Heess and passenger car design chief Max Wagner were finished. In early April there was the first encounter between drivers Rudolf Caracciola and Hermann Lang and their new mount, one of two built, in Hockenheim, resulting in 500 almost trouble-free kilometres. To everybody's surprise the final list of contestants issued by the organisers of the Tripoli Grand Prix on April 11 included two Mercedes-Benz W 165 cars - the brand's first 1.5-liter racing cars since the Targa Florio in 1922.
The immense time pressure haunting the project inescapably triggered practical necessities. The W 165 obviously had to follow the lines established by the up-to-date W 154 Grand Prix car, which, of course, was being feverishly further developed at the same time. Indeed the open-wheel W 165 looked like a scaled-down version of its big brother, 3680 millimetres long (W 154: 4250 millimetres) and with a shortened wheelbase of 2450 millimetres (W 154: 2730 millimetres). The braces of its tubular oval frame consisted of nickel chromium molybdenum steel, its five cross members being complemented by the rear engine support. The driver's seat was slightly offset to the right, and so were the windshield and the rear-view mirrors. As on the W 154, the propeller shaft was angled though, because of the cramped conditions, it had been impossible to create the space for the customary central position. What's more, the seat was positioned farther forward, as Wagner wanted to stow away as much petrol as possible within the confines of the wheelbase. Again there was the tank in the tail, as well as a saddle tank above the driver's thighs. Topped up but without its driver, the W 165 weighed a mere 905 kilograms, 53.3 percent of which were placed above the rear axle.
The engine, weighing just 195 kilograms, could not deny its kinship with the W 154's V12. It was a compact 1493 cc 90-degree V8 with four overhead camshafts and 32 valves, its valve gear and arrangement being almost identical with the Grand Prix engine's. Its right-hand bank was offset forward by 18 millimetres, either bank consisting of four combustion units sharing a common base plate and (glycol) coolant jacket. The heads were welded together with the cylinders. Tests with a centrifugal supercharger were discontinued as boost pressure dropped quickly at low revs. So the mixture formation system was made up by two Solex suction-type carburettors, powerfully assisted by two Roots blowers. Its 254 hp (187 kW) at 8250 rpm were equivalent to a power-to-swept-volume ratio of 170 hp (125 kW) - indeed an impressive value. Their taming had been efficiently looked after as well, as huge brake drums (with a diameter of 360 millimetres) filled almost the complete interior of the wire wheels. Even the heat of the Libyan host country (52°C on racing day) had been allowed for in that the fuel feed lines were guided through a tubular radiator.
The rest is racing history at its very best. The Mercedes-Benz W 165 cars gave their opponents no break. Caracciola, on fresh tires, raced right through with his short-ratio car, while Lang with his "long" rear axle ratio (and thus a higher top speed) made one quick pit-stop and won the Tripoli race almost one lap ahead of his team-mate. He might have lapped him but then his scruples prevailed - one cannot do that to this man. Times were different then.