In 1968, the rules were changed, so that prototypes were limited to 3.0L, but Sports cars of up to 5.0L could still be entered. It was also announced that the minimum production figure for the Group 4 sports cars would be reduced to 25 cars for 1969. With larger engines than the prototypes, the Group 4 cars were now in contention for outright race wins. The Ford GT40 was the winner at Le Mans in both 1968 and 1969. Porsche began work on a production run of 25 cars for the Porsche 917. Ferrari, with some financial help from Fiat, produced the similar Ferrari 512.