Know Formula 1 • Episode 07
Free Practice: What Teams Actually Test in FP1, FP2, and FP3
Looking at the timing sheets during Friday practice can be misleading. The fastest car on Friday afternoon rarely starts on pole on Saturday. Free practice is not about setting ultimate lap times; it is a testing exercise designed to solve three critical equations.
1. Short Runs vs. Long Runs
During practice, teams alternate between two diametrically opposed vehicle states:
- Short Runs (Qualifying Sims): Low fuel loads (10–15 kg), maximum engine mode deploy, softest tyre compound, testing pure single-lap mechanical grip and braking stability.
- Long Runs (Race Sims): Heavy fuel tanks (80–100 kg), conservative power unit deployment, running 15 to 20 consecutive laps to monitor how quickly the tyres thermally degrade.
2. Aero Rakes and Flow-Vis Paint
In FP1, cars frequently emerge with massive metallic grids mounted behind the front wheels (kiel probe rakes) to record physical airflow pressure deltas, comparing real-world wind behavior to CFD (computational fluid dynamics) models. Fluorescent green or paraffin paint (Flow-Vis) is also painted onto wings; as the car speeds down the track, the wind streaks the paint, showing aerodynamicists exactly where airflow detaches or stalls.