Doing the entire F1 effort yourself is an extremely difficult challenge, and only Ferrari and Renault have had any success at it. Ferrari's current situation took years to build up after a long period of failure, while Renault simply integrated the existing Benetton effort into their own fairly seamlessly. They have been able to invest much mroe than Ford, in terms of top personnel and drivers, as well as having experience as a company.
Supplying engines is well within Ford's range - maybe they can go back to having one top-level engine for a big team, and anotehr cheaper one for the smaller teams.
|