The first outing for the P83 came at the first race of 1966 in Monaco, Stewart trying out the car in practise before driving a P261 to victory in the race. In Belgium both Hill and Stewart practised with the P83, both opting to use the P261 in the race, Stewart having his infamous crash at Masta which put him out of the next race in France. Two P83s were now available and around the fast Reims circuit Hill set a time which would have been good enough for fourth on the grid, but started eighth in the P261 instead after having gearbox problems.