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.