Today’s announcement that Ford is returning to endurance sports car racing with its GT model, allied with Wednesday’s news that BMW is considering a Le Mans assaultshould cause a few furrowed brows in Formula 1 circles.

Why? Simply, because there is a very small pool of car manufacturers with the resources to enter expensive top-line motor racing. The fact is, the more that commit to sports cars and other championships, the fewer there are to consider Formula 1, which costs enough to effectively preclude a manufacturer from establishing any other major competition projects.

You can't blame Ford and BMW. Together the FIA and ACO, who set the endurance racing rules, have come up with a very appealing set of regulations that achieve the almost impossible feat of moderating performance and controlling costs, but leaving enough room for engineering innovation.

That much can be seen by the fact that the four major teams at this year’s Le Mans race – Porsche, Audi, Toyota and Nissan – have all chosen different technical approaches to crack the same nut.

Similarly, the likes of Aston Martin and Corvette (and now Ford) use the more-standard Le Mans GT category to prove the potential of their high-performance road cars on the track.