In 1954, the world championship adopted a 2.5-litre engine formula whose cack-handed introduction had led directly to grands prix having to be opened to Formula 2 cars only for the preceding two seasons. The idea behind advertising the new rules well in advance, in late 1951, had been to give manufacturers time to prepare; instead, many of the existing entrants bailed out, unwilling to invest in building new cars which would be obsolete after just two seasons of competition.
While the 2.5-litre regulations did attract new entrants, many of them missed the start of the 1954 season because they still weren't ready, despite the notice period.
