requirement meant that cars needed to conserve fuel early in the race, manufacturer support for the new regulations grew steadily with each make adding to the diversity of the series. With the new rules, it was theoretically possible for large naturally aspirated engines to compete with small forced induction engines. In addition, all races were to be contested over at least 1000 km -- usually lasting more than six hours -- so it was possible to emphasize the "endurance" aspect of the competition as well.

Ford (with the C100)