During these unofficial testing days everyone times everyone else and some exaggerated claims are made as a form of “gamesmanship”. Tyres are tested to settle on the most suitable type for the race and suspension, aerodynamics and general handling are all played with in search of the ultimate, consistent lap time.
Some cars, such as the six-wheeled Tyrrell Project 34/2 covered as much as 500 miles, well over 200 laps of the wiggly Autodrome. After all this you would expect each driver to give himself a few shake-down laps when official practice began, and then set a lap time suitable for a good grid position. However, it doesn’t seem to work like that and most drivers used the four practice sessions to the full, clocking up 130 or 140 laps in preparation for a 75-lap race.
One of the problems is that with everyone practising, a driver is lucky to get 10 good, fast, single flying laps out of a total of 40 or more, and then only if he has a trouble-free session.