1939 Was the first year of the new 3-litre supercharged / 4½-litre unsupercharged GP Formula. Strictly this was a sliding scale Formula designed to place cars of all engine sizes from 666 c.c. to 4,500 c.c. on a level footing, but only Germany’s blown 3-litre twelve-cylinder Mercedes and Auto Unions had the performance to win, albeit at the cost of heavy fuel and tyre consumption. By the time the 11th German GP came round the situation had settled down with Mercedes the dominant marque. Auto Union, demoralized by the grievous loss of Bernd Rosemeyer in a record attempt, tagged along behind, Maserati were an erratic threat with a fast new eight-cylinder 3-litre, and France’s V-12 Delahayes had proved slow but reliable and easy on tyres and fuel.
