Every drive, recorded from the car itself.
OBDTrip is an iPhone app for the OBD-II port under your dashboard. Plug in a Bluetooth adapter, set the app up once, and from then on each journey is recorded on its own: the route, the speed, the revs, the temperatures, the fuel and any fault codes. You don't open the app to start a trip and you don't stop it at the end.
- iPhone, iOS 26
- CarPlay
- Lock Screen and Home Screen
- No account
One drive, start to finish
A Wednesday commute from Rugby to Warwick: 22 miles and about forty minutes, mostly on the A45. This is what happens on the phone and in the car.
The phone stays in your pocket
When you switch the ignition on, the adapter wakes up and iOS wakes OBDTrip for it, even if you haven't opened the app for weeks. It finds the car by its VIN, checks which readings that car answers to, and starts recording. A Live Activity appears on the Lock Screen so you can see that it has.
The first time you connect a car this takes a little longer, because the app asks the engine what it supports. After that it remembers, and goes straight to recording.
On the car's screen, if you want it there
With CarPlay connected, OBDTrip puts up to eight readings on the car's display. You choose which, and how each one is drawn: a big number, a dial, a bar or a small graph. The other tabs list what has happened on the drive so far, let you reorder the readings, and show the connection.
There is no map tab. A CarPlay app of this kind can't draw a proper moving map, and a pin that doesn't follow the car is worse than nothing. Your sat-nav does that job already.
Turn the phone sideways
In a cradle, the Current screen becomes a dashboard sized for a glance at arm's length, with the map beside it. It keeps the screen awake while a drive is being recorded, and only then.
The Dynamic Island keeps an eye on it
Switch to another app and the drive sits in the Dynamic Island: speed on one side, revs on the other. Press and hold for more. The readings it shows are the ones you picked for the Live Activity.
If the coolant runs hot, the fuel gets low or a new fault code turns up, you get one notification. Everything else that's worth knowing waits until you've parked.
The trip closes and names itself
When you switch off and walk away, the drive is finished, worked out and filed under the day as "Rugby to Warwick". The route goes on a map with the moments that mattered pinned on it: the top speed, the hardest braking, where the engine reached temperature.
None of this needs a signal. The phone talks to the adapter directly, the trip is worked out on the phone, and iCloud syncs it to your other devices whenever it next can.
A look round the app
Pick a part of the app. Every picture is a screenshot of the app itself; tap one to see it full size.
Trips
Every drive in one list, newest first, grouped by day and then by month once they're older. Each one is named after where it started and ended. Small marks on the right tell you which drives had a fault code, an alert or laps of a circuit, without opening them.
- Summary. Distance, moving and stopped time, top and average speed, climb and descent, fuel used and economy.
- Warm-up. How long the engine took to reach temperature, and how far you'd driven by then.
- Temperatures. Lowest, usual and highest for coolant, oil, intake air and outside air, on one chart.
- Acceleration. 0–60 mph and 0–100 km/h times, when a drive includes a clean run from a standstill.
- Custom trips. Join a weekend away or a day of deliveries into one trip, with the end date in the future if you like.
- Two cars or more. Filter the list to one vehicle. Each car keeps its own history, recognised by its VIN.
Graphs
Everything the car reported, second by second, for the whole drive. Put up to ten readings on one graph, pinch to zoom into a minute, and drag along it: the map follows and shows where you were at that moment.
- Events on the timeline. Peaks, hard acceleration and braking, alerts, laps and your own markers are drawn on the graph where they happened.
- Exact values. Double-tap anywhere for every reading at that second.
- Turn it sideways for a wider graph with the route alongside.
- Mark a moment while driving with one tap, and find it again on the graph and the map later.
Track days
If a drive goes round the same loop several times, OBDTrip works out that it was a circuit, finds a start line and times every lap. You don't have to tell it you're at a track. Here it's seven laps of the Silverstone Grand Prix circuit in an MX-5.
- Best lap highlighted, with top speed and highest revs for each lap.
- Compare laps side by side on the graph.
- Move the line. If the start/finish isn't where your timing beam is, put it somewhere else and the laps are timed again.
- GPS based. Times are as good as the phone's GPS: fine for seeing where you're quicker, not for settling a championship.
Insights and "Is this normal?"
Over weeks and months the app builds up a picture of what's normal for your car: how warm the coolant usually runs, the charging voltage, how far the fuel trims sit from zero. Each drive is checked against that picture, and each car's Insights page shows the totals for whatever period you pick.
- Any period. Last 7, 30 or 90 days, this year, or everything, for one car or all of them.
- Tiles you choose. Economy, fuel, CO2, distance, time driving, warm-up, battery voltage, top speed. Remove the ones you don't care about.
- Trends. A slow change, like a warm-up that's getting longer, is pointed out once it's clearly real, not after one odd drive.
- All your trips on one map for the period you've chosen.
Fault codes
OBDTrip reads stored fault codes at the start of every drive and notices when one appears or goes away. Each code comes with a plain explanation, whether it's safe to keep driving, common causes, and its history on that car: when it first appeared, how often it's come back, and what the engine was doing each time.
- Clearing codes. Once a fault is fixed you can clear the codes and turn the engine light off from the phone. The app tells you first that this also erases the freeze-frame data a garage would use.
- Kept in the history. A clear is recorded too, so you can see if a code comes back afterwards.
- Read-only otherwise. Clearing codes is the only thing the app ever sends to the car that isn't a question. No coding, no actuator tests.
Widgets, the Lock Screen and CarPlay
Most of the time you won't open the app at all, so the readings you care about can go where you'll see them anyway. Each surface has its own choice of readings.
- Home Screen widget. Four readings, small or medium. Live while you drive, and the last trip's averages afterwards.
- Live Activity. On the Lock Screen and in the Dynamic Island for the length of the drive, then gone.
- CarPlay. Up to eight tiles, each with its own refresh rate and style.
Sharing a drive
Send a drive to someone as a link. They can open it in any browser, or in OBDTrip if they have it. You decide what goes in it before the link is made.
- Where it went. Nothing, just the place names, the shape of the route with no map under it, or the full route.
- Which readings and which moments go in. Anything left out isn't hidden on the page; it isn't in the file at all.
- How long it lasts. A day, a week, a month. You can take a link down whenever you like.
- As a file. Export a whole trip as an
.obdtripfile and open it on another device.
Why keep months of drives?
One reading on its own tells you very little. A few months of them can tell you something's changing before the car does. Here's the MX-5 from the screenshots.
- August. Every Sunday drive to Stratford looks the same: the engine is warm within about eight minutes and the coolant settles in the low nineties. That becomes the car's normal.
- September. Warm-ups start taking longer. There's no warning light and nothing you'd notice from the driver's seat.
- Early October. P0128 turns up on a Sunday morning drive, "coolant thermostat below regulating temperature", and clears itself a week later. Easy to shrug off.
- Mid-October. "Is this normal?" marks the latest drive's coolant as lower than usual, and Insights has the coolant warm-up up 48% on its usual figure. On the way home from Stratford, P0128 comes back, and its history sits next to those two charts. It's the thermostat sticking open.
That's the sort of thing the app is for. It doesn't diagnose anything, but it notices when your car stops behaving like itself and shows you the evidence.
What's new
What each update brings, in a few lines: the same list you'll see in the App Store. Updates are always free.
Version 1.1
- Readings from the manufacturer's own computers: battery health and charge on the Kona Electric and Niro EV, and particulate filter soot on VW group diesels, with a heads-up when a filter clean is cut short.
- Tesla support: plug in a Bluetooth adapter and OBDTrip works out what your Tesla shares, with live readings where the car offers them and its 12 V battery voltage always.
- A health summary for each car: one line on whether anything needs a look, then green, amber or red for faults, coolant, oil, battery, fuel trim and fuel.
- Will it pass its MOT or smog test? See the car's emissions self-tests at a glance, and what usually completes each one.
- Thinking of buying a car? Plug in for a used-car check that shows whether its codes were cleared recently, ready to share as a PDF.
- Early warnings: pending codes before the check engine light comes on, plus permanent codes and the freeze frame, kept for you even when you clear codes.
- Tap any amber or red line for the full story, ready to hand to a mechanic: the readings, likely causes and what to check first.
- Insights now live on each car's own page, with "Is this normal?" and the fleet comparison for that car alone.
- "What OBDTrip watches": everything the app keeps an eye on for your car, and which readings your car supplies.
- Coolant and oil graphs mark where your engine normally runs, on the phone, in CarPlay, on the Lock Screen and in the widget.
- Engine torque and power, worked out from what your engine reports.
- Around 80 more readings, from fuel pressures and exhaust temperatures to every oxygen sensor and the odometer on newer cars.
- Works with more Bluetooth adapters, and better with older, Asian-market, stop-start and hybrid cars.
- Better with several cars or adapters: OBDTrip waits for every adapter you use, and keeps each car's details with the car, whichever adapter it has.
- No more phantom trips from a parked car with the adapter awake.
- Tidier screens: sections fold away, a cleaner Trips list with a simple mark on shared drives, and your subscription right inside Settings.
- Tap a car's VIN to copy it.
The details
What you need, what it reads, and what it costs.
| Phone | An iPhone on iOS 26 or later. |
|---|---|
| Adapter | A Bluetooth Low Energy OBD-II adapter that speaks the ELM327 command set. Developed and tested with the Vgate iCar Pro Bluetooth 4.0, and recognises most other common BLE adapters. Classic Bluetooth and Wi-Fi adapters can't be used: iOS won't let an app reach them in the background. |
| Car | Anything with an OBD-II port. In the UK and EU that's most petrol cars from 2001 and diesels from 2004; in the US, cars from 1996. Teslas too: OBDTrip listens to what the car shares, with live readings where its port offers them and the 12 V battery always. |
| Permissions | Bluetooth, and location set to "Always". Without "Always", iOS won't let a drive start while the app is closed. |
| Units | mph or km/h, °C or °F, mpg (UK or US) or L/100km, psi, bar or kPa, 12 or 24-hour clock. |
| From the car | Speed, revs, engine load, throttle and pedal, coolant, oil and intake temperatures, outside temperature, airflow, manifold and fuel pressures, fuel level, fuel trims, voltage, run time, torque, catalyst temperatures, oxygen sensors, EGR, hybrid battery and, on newer cars, the odometer. Whichever of these your car supports; the app asks. |
|---|---|
| From the phone | Route, altitude and GPS speed during a drive. Acceleration and cornering forces from the phone's motion sensors. |
| Worked out | Fuel used, economy and CO2, engine torque and power, warm-up time, 0–60 times, climb and descent, laps, a health summary for each car, and how each drive compares with the car's usual. |
| Fault codes | Stored codes and the engine light at the start of every drive, with their history per car. |
Free, and the subscription
Free
Enough to check the app works with your adapter and car before you pay anything.
- Connects and identifies your car
- Recognises every drive
- Speed and revs live while you drive
Subscription
Monthly or yearly, through the App Store. Cancel in your Apple account settings.
- Every drive recorded in full: route, readings, events, laps
- Trends, "Is this normal?" and alerts
- Read and clear fault codes
- Sharing and export
Privacy
A record of where you drive, when, and how, is the kind of thing that shouldn't sit on someone else's server. So your drives stay on your iPhone and in your own iCloud, where they sync between your devices. There's no OBDTrip account, and we can't see your iCloud data.
Kept on your devices
- Your car's VIN
- Every route, and when you drove it
- The second-by-second readings
- Fault codes and their history
- Names and photos you give your cars
Never sent to us
- Your location, in any form
- Your VIN or registration
- Journey times finer than the hour
- An email address, name or password
- Anything for advertisers. There are none.
What does reach our server
Essential diagnostics, always: that the app was opened, that a drive happened, roughly how much it's storing, and what went wrong when something did. That's how a problem on your phone gets fixed in the next version. Nothing in it identifies you, your car or where you've been, and it's never finer than the hour.
Extended telemetry, which is your choice in Settings, for a day, a week, a month or until you turn it off: detailed readings, so the app can tell you whether your car is normal compared with others like it. Turning it off stops collection straight away, but can't take back readings already averaged in with other cars. It's labelled with a broad group (this engine family, these model years) worked out on your phone. The VIN it came from never leaves the phone, and no figure is published until enough cars stand behind it.
A shared trip holds only what you put in it, and is deleted when the link ends. The full detail is in the privacy policy.
Questions
Which adapter should I buy?
The app is developed against the Vgate iCar Pro Bluetooth 4.0, which costs about £20 and is the one to get if you don't already have one. Other Bluetooth Low Energy adapters that use the ELM327 command set work too. If your adapter pairs in iOS Settings with a PIN like 1234, it's a Classic Bluetooth one and won't work; neither will Wi-Fi adapters.
Will the adapter flatten my battery?
An adapter draws a little power from the port whenever it's plugged in, whichever app you use. Most go to sleep when the car does. If a car is going to stand for weeks, unplug it. OBDTrip itself stops asking for readings as soon as the engine stops answering.
Do I really never have to open it?
Once it's set up, no. iOS starts OBDTrip in the background when the adapter appears. The one exception is Apple's: if you swipe the app away in the app switcher, iOS won't start it for Bluetooth again until you've opened it yourself.
A drive was split in two, or one is missing.
A short Bluetooth drop-out during a drive carries on as the same trip; a long one starts a new one, which is usually why a journey looks split. A missing drive is nearly always the swiped-away case above. Support has the rest, including the connection log, which shows exactly what the phone saw.
Can it clear the engine light?
Yes, from the Fault Codes screen, once the fault's been fixed. Clearing also wipes the freeze-frame data and resets the emissions readiness monitors, so do it after a repair rather than instead of one. A fault that's still there will come straight back.
What if I have more than one car?
Use the same adapter in each, or one per car. OBDTrip recognises each car by its VIN and keeps its drives, normal ranges and fault history separate. There's nothing to switch.
What happens to my data if I delete the app?
It goes from the phone, and Settings → Privacy can remove the iCloud copy in the same step. We don't hold a copy of your drives, so there's nothing to ask us to delete.
Recent changes
OBDTrip has been in development since August 2026. The latest work, newest first:
- Battery Saver: lighter recording for an older phone or a long day, and it follows Low Power Mode on its own. Trends now lead with the verdict, and "Is this normal?" is in plainer English.
- Back up everything to one signed file, and restore it exactly.
- Trips and Insights share one vehicle filter. Swipe a trip in the list to share it.
- CarPlay gets a Connection tab, and the app keeps trying to connect without getting stuck.
- "Is this normal?": every health reading drawn against the car's own usual range. A warning when a drive gets no GPS.
- A warm-up indicator on the dashboard, graphs in the widget, and more cars recognised.
- Drives that start with the app closed are recorded, and the app tells you if something would stop that happening.
About the screenshots. They're all taken from the app running in Apple's iOS Simulator, with nothing drawn or retouched afterwards. A Simulator can't plug into a car, so the app is connected to a simulated ELM327 adapter that answers its requests from a drive along real roads near Rugby, while the Simulator's location follows the same route. The ten weeks of earlier drives in two cars were made the same way and processed by the app exactly as recorded drives are. The garage is invented; the app isn't.