Trip meters
For course cars, sweep cars and anyone following a route book: as many trip meters as you need, measured from GPS speed, in miles or kilometers.
Using them
- Open the menu and tap Trip meters. Add a meter with +, and give it a name if you like. It starts counting from there.
- Switch measuring on. The meters keep counting with the screen locked in its mount, and while you use other apps.
- Reset takes a long press, and offers Undo.
- Switch between miles and kilometers at the top of the screen.
- Switch measuring off when the phone leaves the car. Carrying it on foot counts as distance, and indoors some phones pick up weak satellite signals and count those too.
Keeping them running
- Don't swipe Rally Clock away in recent apps while measuring. Switching to other apps is fine; swiping it away closes it. If that happens, it starts measuring again when you reopen it, but the distance driven in between is lost.
- On Android, a notification shows while it measures. On an iPhone or iPad, the location indicator does.
- Samsung, Xiaomi, OnePlus and some others close apps to save battery, even while they measure. Set Rally Clock's battery use to Unrestricted (Settings → Apps → Rally Clock → Battery). On Samsung, also add it to Never sleeping apps (Settings → Battery → Background usage limits).
Calibrating against an odometer check
Out of the box, the meters read what the GPS measures. To match an event's distances, calibrate against its official odometer check:
- Use the event's official check, of at least 3.1 miles (5 km), not your car's own odometer.
- Switch measuring on before the start, and leave it on the whole way. Reset a meter as you pass the start.
- At the end, tap Calibrate (the sliders icon), choose From an odometer check, enter the Official distance, pick the meter you drove with, and tap Use this factor.
Every meter is then corrected by that factor. If you already know yours, use Enter a factor instead. A factor runs from 0.9 to 1.1, because a GPS is never out by more.
What they need
A GPS: phones have one, and so do the cellular models of iPad. Wi-Fi-only iPads and most computers don't. Location permission is needed, and your position is never stored or sent.