What is an analog speedometer?
The same GPS engine, drawn as a real instrument. A 264 degree sweep, a needle with a drop shadow, major and minor graduations, a red zone from your alert speed up, and a small amber marker left at the fastest point you reached.
It even does the startup sweep, the full swing to maximum and back that a car does when you turn the ignition on. On a real car that's a self-test. Here it's honest theatre, and you can turn it off.
Why does a needle still win?
Digital displays replaced dials almost everywhere, and then cars with fully digital clusters started drawing dials on them. That isn't nostalgia. It's what the display is for.
A needle encodes speed as an angle, and angle is something your peripheral vision reads without being looked at. You don't read a dial, you notice where the needle is. A number has to be read, focused on and interpreted, and every one of those costs attention you'd rather spend on the road.
- Rate of change is free. A needle sweeping quickly tells you you're accelerating hard, with no comparing of values.
- Distance to a limit is visible. The gap between needle and red zone is a picture, not a subtraction.
- It stays readable while it moves. Digits changing several times a second become unreadable. A needle just moves.
- Muscle memory works. After a few drives, "about there" becomes a speed, with no reading at all.
What the markings mean
| Element | What it shows |
|---|---|
| Blue arc | Speed from zero to now, filled as you go |
| Red zone | Everything above your speed alert |
| Amber tick | The fastest point reached since the last reset |
| Long marks | Labelled graduations |
| Short marks | Minor graduations between them |
| Centre figure | The same speed as a number, for when precision matters |
| Small figure below | Distance covered |
Why does the top of the dial change?
A gauge is only readable if the needle uses most of its sweep. A 240 km/h face is useless on a bicycle, where the needle never leaves the first eighth.
So it starts at a sensible range for the page and steps up as you go faster. And it's defined in absolute terms rather than in whatever unit you picked, so switching to mph rescales the whole face to mph numbers instead of showing you a nonsensical conversion. Pin it to a fixed value in settings if you'd rather it never moved.
Smoothing
A raw GPS reading makes the needle twitch, because the measurement is uncertain by a km/h or two and updates about once a second. Medium is the default and looks like a real instrument. Heavy is calmer and lags a bit more. Raw is there if you want to see exactly what the receiver reported, twitches included.
Frequently asked questions
Is the dial less accurate than the digital display?
No. Both draw the same GPS reading. The dial is easier to read at a glance and shows rate of change. The digital display is easier to read exactly.
Why does the top of the dial keep changing?
So the needle always uses most of its sweep. Pin it to a fixed value in settings if you prefer a constant face.
What is the small amber mark?
A peak marker, left at the fastest speed since the last reset. Same idea as the telltale on a mechanical tacho.
Can I turn off the startup sweep?
Yes, in settings. On a real car it's a self-test. Here it's decoration, so it's switchable.
Why does the needle lag when I accelerate?
Two reasons. GPS reports about once a second, and the default smoothing damps the movement on purpose. Set smoothing to raw to see the unfiltered reading.