65. It’s the new 35
When Paul Newman was 65, he was scoring top-10 results in Trans-Am. At 70, he was third in GT in the Rolex 24 at Daytona. When he was 78, PLN finished second-in-class (8th overall) at the Grand-Am Watkins Glen race. Morgan Shepherd, Jim Fitzgerald and Hershel McGriff all were racing at 65+. John Force and Jack Baldwin are still racing. There are countless vintage racers 65 and older.