TopGear.com at F1 testing in Jerez
The actual act of testing is split over four days at Jerez, and is the first opportunity for teams to get to grips with their new cars.
The first day is straightforward: a case of getting the car out and checking they haven't put the rear wing on the front, the front on the rear and connected the driver's water bottle into the radio jack instead of their helmet. Once those boxes are ticked, events rapidly progress to get mechanics and drivers dialled into the new car.
Only one car is used, and drivers alternate over days (unless you're Fernando Alonso, who skipped this session entirely). Then it's about putting the first kilometres on the cars and gathering data. On a good day, teams want to do 65 to 100 laps, testing various bodywork, mechanical and tyre options to see what works, and what doesn't.