User Guide
From the GPS speedometer and ODO/TRIP tracking to fuel management, carburetor tuning records, torque specs, oil change records, and maintenance records — here's what each of the 5 tabs can do, with screenshots.
Cars
Start by registering your car in the Cars tab. You can register multiple vehicles and switch between them — trip logs, fuel records, tuning records, and maintenance records are all kept independently per vehicle.
Open the registration screen from “+ Add Vehicle” in the vehicle list. Enter a name and year, and choose the model/engine from the dropdowns — if your car isn't listed, tap “+” to add it on the spot.
Cars tab: vehicle list
New registration form
Match the speedometer's background color to your car's interior. Just pick a color from the color picker in the registration form, and it's reflected on the Drive screen.
Custom color setting
In simple (immersive) display, you can place your own image above and below the meter. Transparent PNGs work best for emblems or logos. Adjust size and distance (position from the meter) with the sliders.
Meter custom image
Tap a vehicle in the list to open its detail screen, where you'll find entry points for “Maintenance,” “Tuning Records” and “Torque Specs.” From here you can view and add records specific to that vehicle.
Vehicle detail screen
If you fit tires of a different size from stock — for a lowered car, for example — your car’s odometer and speedometer no longer match the actual distance and speed (smaller tires make them read high). The app measures the actual distance by GPS, so its numbers drift away from your car’s.
Turn on “Match my car’s odometer” under “Odometer Correction” on the vehicle edit screen, and the app counts ODO and TRIP to match your car’s odometer.
| Item | What it does |
|---|---|
| Stock tire diameter Current tire diameter | Enter in mm. You can find the diameter in the tire maker’s size chart (inches × 25.4 = mm). |
| Fine-tune | Use the + / − buttons to change it in 0.5% steps, for when the diameters alone don’t quite match (an error in the gauge itself, for example). Use a plus value if your car’s odometer runs ahead, a minus value if it runs behind. |
| Match my car’s speedometer | When on, the thick needle and the SPEED reading also match your car’s speedometer. The actual speed is shown by a thin red needle. |
As you enter the values, the screen shows “Your car’s odometer reads about ◯% more than the actual distance.” When you save, you’ll be asked whether to match the app’s ODO to your car’s odometer now — enter the reading on your car’s odometer and tap “Match my car,” and the app counts from there with the correction. While the correction is on, the ODO and TRIP labels in the info bar on the Drive screen turn red.
Odometer correction
Drive screen with the correction on
The vehicle detail screen also shows the “Actual distance.” To stop the correction, turn it off and save — you can choose to set the app’s ODO back to the actual distance or keep the app’s ODO.
Tips for matching: reset TRIP, drive 10 km or more (at a steady speed if you can), then compare how far your car’s odometer moved with the app’s TRIP. If there’s still a difference, adjust the fine-tune value a little at a time. The correction is a percentage, so the gap between the two needles widens as you go faster.
Maintenance
Keep a complete log of inspections, repairs, and servicing. Quickly check things like “When did I last change the tires?” or “When was the last inspection?” Access it from “Maintenance” on the vehicle detail screen.
Record the date, mileage, category (choose from the dropdown, or add a new one with “+”), work description, cost, shop, and notes. You can also filter the list by category.
Maintenance list
Maintenance form
Setting Record
From “Tuning Records” on the vehicle detail screen, log your carburetor adjustments. Keeping before/after data means you can instantly return to the setup that worked best.
Choose the carb type (dropdown, or add one with “+”) and set the number of carbs (1–8). Jet sizes can be set as “same for all carbs” or “individually,” supporting multi-carb setups.
Record the turns for the air and fuel screws individually. Enter a baseline setting and the app automatically calculates and displays the change in turns and degrees. Also record the resulting mixture (rich / good / lean) and temperature (low / good / high), plus any notes.
Tuning records list
Tuning record form
Torque
From “Torque Specs” on the vehicle detail screen, keep the tightening figures for this particular car. Where maintenance and tuning records log what you did and when, this one holds what the car is. There are no dates — it is a table you build up and edit, one entry per fastener.
Pick the area (dropdown, or add one with “+”), name the fastener, and enter the figure with its unit. Engine, Drivetrain, Suspension, Brakes, Steering, Electrical and Body are provided; add your own with “+” whenever something doesn't fit.
You can also record the bolt size (M8 and so on), the source the figure came from, and notes on sequence or stages. For something like head nuts, tightened in stages, writing “stage 1 at 1.5, stage 2 at 3.0” into the notes saves you looking it up mid-job.
Torque specs list
Torque spec form
“Display unit” at the top of the list switches between N·m, kgf·m and lb-ft. Every figure you have saved converts the moment you press it.
What you typed, though, stays exactly as the manual wrote it. Only the display converts. Enter “3.0 kgf·m” as printed, switch to N·m, and you get “29.4 N·m” in large type with a small “(3 kgf·m)” beside it — so the app and the book still agree.
The buttons above the list narrow it to a single area. Choose “All” and everything appears under area headings, so it reads top to bottom like a spec table.
Drive
Displays real-time speed via GPS and automatically tracks ODO (total distance) and TRIP (segment distance). With background GPS, tracking continues even while using other apps.
By default, tracking starts automatically whenever the app is open. Turn on “Manual Start/Stop Tracking” in the Settings tab to control tracking yourself with the START/STOP button on the Drive screen.
Drive screen: normal display
Waiting to START (manual mode)
Turning on “Background GPS” in the Settings tab keeps tracking distance even when the screen is off or you're using another app (like navigation or music). When off, tracking only happens while the Drive screen is open.
The meter dial has three display modes. You can switch between them by swiping left or right on the meter. The dots at the bottom indicate the current mode.
Fuel gauge mode
Clock mode (Classic)
The clock comes in two designs, “Classic” and “Cockpit.” Choose one for each vehicle under “Clock Design” on the vehicle edit screen. Cockpit has a black face and red hands, like an add-on gauge fitted to a classic car.
Clock mode (Cockpit)
Tap the FUEL mark at the bottom right of the Drive screen (the right end of the info bar) to look for the nearest gas stations in your own map app. The same mark blinks orange when fuel is running low, so it is right there when you need it.
A confirmation appears first, and "Search" switches to the map app. Brushing the mark while driving will not throw you into another app.
You can choose which map app opens under "Map App" in Setting.
Flip the switch in the bottom-right of the meter to enter immersive mode, showing the meter alone in full screen — great for visibility while driving. Tap again to return to the normal view.
Immersive display
Press “PW SAVER” on the info bar and the gauge disappears, leaving the screen black. You’ll be asked to confirm first — choose “Yes”.
Speed, ODO and TRIP stay on the info bar and tracking carries on exactly as before, so nothing you need while driving is lost. “Back to normal view” in the middle of the screen restores the gauge whenever you like, and the normal view comes back automatically once measurement ends — whether you press STOP or it finishes through Bluetooth or NFC.
The info bar is hidden in immersive display, so return to the normal view before pressing PW SAVER.
The app supports a custom URL scheme starting with “vcmonitor://”. Write this URL to an NFC tag and place it on your dashboard, and tapping your phone against it will automatically open the specified screen — handy for starting tracking the moment you get in.
URL for each screen
| URL | Opens |
|---|---|
| vcmonitor://cars | Cars (vehicle management) |
| vcmonitor://drive | Drive (speedometer screen) |
| vcmonitor://fuel | Fuel (fuel tracking) |
| vcmonitor://oil | Oil (oil change records) |
| vcmonitor://setting | Settings |
| vcmonitor://stop | Stop measuring and save the trip |
Opening a specific vehicle
Add ?car=VEHICLE_ID after “vcmonitor://drive” to switch to that vehicle before opening the Drive screen. Keep a tag per car and you'll never have to re-select the vehicle when you swap. The URL with the vehicle ID is shown for each car under Setting → Bluetooth Link in the app — just copy it from there.
A tag that ends the trip
“vcmonitor://stop” stops measuring and saves the trip — meant for tapping as you get out. Nothing happens if you tap it while no trip is being measured.
Writing an NFC tag
Writing to an NFC tag isn't a feature of this app itself — you'll need a general-purpose NFC writing app. Write the URL above to the tag as a “URL/URI record.”
When your phone connects to your car's Bluetooth audio, the Drive screen opens as you get in, and the trip ends with the distance reported as you leave. There's no extra hardware to buy — the car audio you already have, or a Bluetooth adapter in the cigarette socket, does the job.
What you need
iPhone setup
Build two automations in the Shortcuts app — one for getting in, one for getting out. First open Setting → Bluetooth Link in the app and tap “Copy” on the URL for your vehicle.
1. Getting in
2. Getting out
Android setup
Open Setting → Bluetooth Link, tap “Select” next to a vehicle and choose one of your paired devices. That's all — no shortcuts to build. Getting in, you receive a notification; tap it to open that vehicle's Drive screen.
Notifications
When the trip ends as you leave, you get “Trip recorded (12.3 km) — nice drive!” — nothing to set up. Ending a trip yourself with the STOP button shows the result on screen, so no notification is sent.
Stopping for fuel along the way
The distance so far is recorded and the trip ends. Press START again when you set off. Measuring only ever begins when you press START, so there is nothing to second-guess.
Fuel
Just log the amount and mileage every time you fill up, and the app automatically calculates estimated remaining fuel, range, and average economy — solving the “how much farther can I go?” question for vintage cars with smaller tanks.
Enter it from “+ Add Fill-up” in the Fuel tab. Supports both “filled to full” entries and entries where you know the “remaining fuel after filling.”
Fill-up history + stats
Fill-up form
Once you've logged enough fill-ups, you can view your fuel economy trend as a graph. Switch between “full-tank method” and “interval economy.” Fuel volume (L / US gal / UK gal) and how economy is shown (km/L / L/100km / UK mpg) can be changed in the Settings tab.
Fuel economy chart
A “Share” button appears on any fill-up record where fuel economy was calculated. Tap it to generate a meter-styled image card summarizing that record's fuel economy and distance, then share it or save it via the standard share sheet.
The card's background color uses the custom color you set when registering the vehicle, so your car's personality carries right through into the image.
Fuel economy share card
Oil
Log the date, mileage, brand, and viscosity together in one place. Oil management matters especially for air-cooled engines. Set a reminder interval so you never miss the next change.
Enter it from “+ Add Oil Change” in the Oil tab. Along with brand, viscosity (dropdown, or add one with “+”), and amount, you can also check off whether the gasket and filter were replaced.
Oil change history
Oil change form
Based on the “oil change interval” (distance / time) you set when registering the vehicle, a reminder appears at the top of the Oil tab as the next change approaches. Use it to avoid missing a change.
Setting
Adjust language, units, startup behavior, and GPS behavior to match how you use the app.
| Setting | Description |
|---|---|
| Language | Switch the display language between Japanese and English |
| Distance | Switch the distance unit between km and mi |
| Volume | Switch the fuel unit between L, US gal and UK gal (imperial). Past records are never rewritten |
| Economy | Show fuel economy as km/L (mi/gal when distance is in miles), L/100km (litres used per 100 km) or UK mpg (imperial-gallon mpg; fuel stays in litres) |
| Start | Choose which tab opens when the app launches (Cars/Drive/Fuel/Oil) |
| Drive Display | Set the Drive screen's default display mode (speedometer / fuel gauge / clock). Can be switched temporarily by swiping while driving |
| Manual Start/Stop Tracking | When on, control tracking with the START/STOP buttons. When off, tracking starts automatically while the app is open |
| Background GPS | When on, tracking continues even while using another app or with the screen off |
| Map App | Which map app opens when you look for gas stations from the FUEL mark. Only apps installed on your device are listed (on Android, "Let device choose" opens whichever app you normally use) |
| Night Mode | After dark, light the gauges with a warm bulb glow. Choose how it switches (automatically or by times you set), the light color and how strong the light is |
After dark, the gauges shift to a display lit by a warm bulb glow. It recreates how a vintage instrument cluster looks at night under a small bulb: the light is strongest at the rim of the dial and fades towards the centre, with a soft bulb glow from the rim to around the numbers. The numbers and the needle keep their brightness, so nothing becomes harder to read.
Turn on “Night Mode” in the Settings tab and the options below appear.
| Option | Description |
|---|---|
| Switching | Automatic — works out sunset and sunrise from your GPS position and switches on its own. Set times — switches during the hours you enter in “Start” and “End” below. |
| Schedule | Shown when “Automatic” is selected: the times the gauges are due to light up and go back to normal today (read-only). Until the app has had a position fix it reads “Locating” and switches by your “Start” and “End” times instead. |
| Start / End | Shown when you choose “Set times”. A range that crosses midnight, such as 18:00–06:00, works fine. |
| Light color | Warm bulb / Green. Green recreates the green gauge lighting of the Mexican-built Beetle. |
| Light level | Low / Normal / High. The stronger the light, the further it reaches across the dial and the deeper the color. |
Use “Backup” at the bottom of the Settings tab to export all your data (vehicle info, trip logs, fuel records, tuning records, maintenance records, and more) as a JSON file. When switching phones or reinstalling the app, restore your data by loading that file with “Import.”
Backup
Where the exported file is saved depends on your device:
The file is named with the date, like vcm_backup_2026-10-09.json. Exporting twice on the same day overwrites it with the newer data.
When you import, the app first keeps a copy of your current data. Importing replaces all of your current data, so this lets you go back if you picked the wrong file.
To go back, simply import that copy. And if a file contains anything that can’t be read, the import is cancelled and your current data stays as it is.
Once you choose where to save, the app saves a backup once a day, on the days you open it. It keeps the most recent 14 and replaces the oldest as new ones are made. If you don't drive every day, that still gives you 14 days you actually used the app to go back to.
The location is a folder outside the app, so backups saved there remain even if you delete the app. Choose somewhere that syncs with the cloud, such as iCloud Drive, and your records carry over when you switch phones.
In the Settings tab, turn on “Automatic Backup” under “Backup,” then set a place with “Choose” next to “Auto backup location.”
To restore, load the file with “Import” just as before. Automatic backups are named with their date, such as vcm_auto_2026-09-22.json. They are kept distinct by name from files you export yourself (vcm_backup_…), and the app never deletes a file you exported.
When no vehicle is registered, the Cars tab shows a “Restore from a Backup” button — useful right after moving to a new phone.
Data
Trip logs, fuel economy, and maintenance records are stored on your device, and the app never sends them anywhere. Automatic backups go only to the location you choose.
See our Privacy Policy for details.
FAQ
The app measures the distance you actually drive by GPS. If your car runs tires of a different size from stock, or its gauge has an error of its own, the car’s odometer slowly drifts away from it.
Enter the stock and current tire diameters under “Odometer Correction” on the vehicle edit screen, and the app’s ODO and TRIP will match your car’s odometer. If the diameters alone don’t quite match, use the “Fine-tune” value (see Match your car’s odometer).
If you edit the ODO in a fuel record or similar just to fix the drift, the app treats it as distance driven while the app wasn’t running, so the fuel economy for that stretch reads a little high. We recommend fixing drift with the fine-tune value.
You’ll see this when “Match my car’s speedometer” is on under “Odometer Correction.” The thick needle (and the SPEED reading) shows the speed matched to your car’s speedometer; the thin red needle shows your actual speed measured by GPS. The correction is a percentage, so the gap between them widens as you go faster.
To go back to a single needle, turn off “Match my car’s speedometer” on the vehicle edit screen.
The app takes a GPS fix every second and keeps the screen awake while you drive, so it uses about as much power as a turn-by-turn navigation app. On longer journeys, these four things help.
1. Switch to power saver mode
Press “PW SAVER” on the info bar of the Drive screen and the gauge disappears, leaving the screen black. Your speed and distance stay on the info bar, so nothing you need while driving is lost. “Back to normal view” brings the gauge back whenever you like.
On phones with an OLED screen this makes a real difference, because black pixels emit no light at all — around 98% less light from the screen if you have chosen a bright background colour. (On an LCD screen the backlight stays on regardless, so this particular saving doesn’t apply.)
2. Turn the screen off on long stretches
With “Background GPS” switched on in the Settings tab, your distance continues to be recorded with the screen off. Open the app when you arrive and your trip will be waiting for you. Well suited to motorway miles, where you don’t need to watch the gauge.
3. Keep it charging
A USB charger in the cigarette socket is well worth having — much as you would when running a navigation app. If you use Bluetooth Link, a socket adapter with a charging port built in is a convenient option.
4. Keep it out of direct sunlight
When the phone gets warm, the operating system may dim the screen or limit performance to protect itself. Mounting it away from the top of the dashboard, somewhere air can reach it, keeps things steady.
The search is done by your map app, so no results will appear where that app cannot connect. If you often drive through mountains or other areas with poor reception, it is worth downloading an offline map in your map app beforehand. Map apps that support offline maps, such as Google Maps, can search your surroundings without a signal.
Your position itself comes from GPS, so the app still knows where you are with no signal.
Android — choose "Let device choose" under "Map App" in Setting and it will open in whichever app you normally use. If your device has not remembered a choice, it will ask you each time.
iPhone — iOS has no system-wide way to pick a map app, so only apps the app has been built to support can be listed. Apple Maps and Google Maps are supported today. If there is an app you would like added, please let us know and we will look into it.
No. Sunset and sunrise are calculated from the position your GPS reported and the device clock. Nothing is requested from a server, so it works with no signal and in airplane mode.
Once a position has been obtained it is stored on the device and reused from then on. If the app has never had a position fix, it falls back automatically to the hours you set in “Start” and “End”.
Out of signal range, GPS cannot use network assistance, so the first fix may take longer. Until it arrives the app switches by time, then moves to automatic once the position comes in.
If “Switching” is set to “Automatic”, check that location permission is granted. Without a position fix the app switches by the times you set instead (18:00–06:00 by default).
To match your own hours, choose “Set times” under “Switching” and enter the “Start” and “End” times you prefer.
The GPS speedometer and ODO/TRIP calculate speed and distance from GPS signal. Depending on reception — in tunnels or dense urban areas, for example — there may be some error or delay compared to actual speed/distance.
Check that your device's location setting is set to “Always Allow.” Depending on the device, you may also need to exclude the app from battery optimization in your OS settings — check your device's manual for details. Note that if the OS force-quits the app, tracking can't continue during that time (this is a platform limitation).
Shortcuts builds its list of actions when it launches, so an app you have just installed or updated may not be in it yet. Quit the Shortcuts app and open it again. Note that this action requires iOS 16 or later.
There are two likely causes.
1. The Bluetooth device stays powered
In a socket that stays live, the connection never drops when you switch the engine off, so the trip never ends. Use a socket wired to accessory power.
2. The phone is connected to the car for calls (hands-free) only
Automatic end-of-trip works when your iPhone is connected to the car's Bluetooth for audio (music). If the car stereo is left on AUX or radio, the iPhone still shows “Connected”, but only for calls, and the trip will not end when you switch off the engine. Switch the stereo to Bluetooth audio, or set up the “2. Getting out” automation in “Bluetooth Link: follow you in and out of the car”. It ends the trip even when only hands-free is connected.
Check whether Do Not Disturb is switched on. While it is, several notifications are bundled into one, and tapping it may not open the app.
Open Settings → Apps → Vintage Car Monitor → Notifications → “Bluetooth link” and turn on “Pop on screen” and “Override Do Not Disturb”. This notification will then appear on its own even during Do Not Disturb, and tapping it opens the Drive screen.
The wording varies by device — “Override Do Not Disturb” may be shown as “Priority notifications”.
That is iOS letting you know an automation ran; it does not come from this app. It is worth keeping — it tells you the automation fired even when the phone stays in your pocket. If your automation offers a “Notify When Run” option you can switch it off, though it is not shown on every version of iOS.
Select a vehicle from the list in the Cars tab, and Drive, Fuel, Oil, Tuning Records, and Maintenance will all reflect that vehicle from then on. ODO/TRIP, fuel records, tuning records, and maintenance records are all stored independently per vehicle.
Yes, reinstalling clears the data stored on your device. Export a backup from “Backup” in the Settings tab beforehand, then import it after reinstalling to restore your data. We recommend the same steps when switching to a new phone.
Setting an automatic backup location takes care of this for you. That location is outside the app, so backups remain even when the app is deleted.
No. What you typed is stored in the unit you typed it in. Only the display converts.
Enter “3.0 kgf·m” as the manual prints it, switch to N·m, and you see “29.4 N·m” with a small “(3 kgf·m)” beside it. The figure the manual gave you is never lost, so you can still check the app against the book later.
Android 11 and later does not let an app be given the top of internal storage or the “Download” folder itself. Tap “Create new folder” in the picker, then choose the folder you just made.
The app never sends your data anywhere. Everything is stored on your device, and nothing is transmitted to us or to any server.
Separately from that, you can turn on automatic backup by choosing where it should save (“Backup” in the Settings tab). If you pick a place that syncs with the cloud, such as iCloud Drive, your device's own OS syncs it. Where your data goes is always your choice.
