For accurate times

1. Mount the phone firmly in a holder. It must not move or rotate during the run.
2. Wait for all three lights. Green means calibrated and ready.
3. Use flat, open ground with clear sky. A slope warning appears if the run looks uphill or downhill.
4. Do runs in both directions and compare averages, not single runs.
5. Every driver uses the same phone and mount for a fair contest.

Times are from first movement with no rollout, the same as most European 0–100 figures. US-style 0–60 figures with a 1-foot rollout read about 0.2–0.3 s quicker.