# OBD2 Trip Logger for iPhone: Record Engine Data > Odo records OBD2 engine data on every trip: RPM, load, throttle, temperatures, fuel used and estimated cost, boost and new fault codes, with a second-by-second replay in sync with speed and elevation. App: Odo: Speedometer, Drive & Ride (iPhone, iPad, Mac with Apple silicon, Apple CarPlay, Apple Watch). Free to download: https://apps.apple.com/app/id6759611784 Page: https://speedometerproapp.com/features/obd2-trip-recording Last updated: 2026-10-28 With an OBD2 adapter connected, Odo saves an engine summary with each trip and records RPM, throttle and load every second, so you can replay them in sync with your speed. ## Why it matters A trip log shows where you went and how fast. Engine data shows how hard the car worked to get there: how much fuel the drive used, whether the engine ran hot, and when you were revving high. ## An engine summary for each trip Open any trip recorded with an adapter and the OBD II Summary shows what the engine did from the moment the trip started. - Engine RPM, engine load, absolute load and throttle: maximum, minimum and average - Coolant temperature at the start and at its peak, oil temperature, intake and outside air - Engine-on time and time spent above 5,500 rpm - Peak boost from manifold pressure, and mass air flow ## Fuel and cost per trip Odo works out how much fuel each trip used, from the car’s fuel rate or, when the car doesn’t report it, from airflow. It prices the trip from your last fill-up before it. - Fuel used, peak and average fuel rate - Average and best fuel economy - Estimated cost from your fuel log - Electric cars: state of charge at the start and end of the trip, once you add your car’s battery reading ## Replay the engine in sync Channel Replay plays engine RPM, throttle, engine load and absolute load on one timeline with GPS speed, elevation and G-force. Move to any moment and every chart follows. - One playhead across every chart - Engine channels recorded every second - Detailed recording is on by default and can be turned off ## Faults caught on the way If the check-engine light comes on or a new trouble code appears during a drive, the trip records it. - Check-engine events per trip - New fault codes saved with the trip - Engine data syncs with your trips through iCloud - Export the summary or the second-by-second data ## How to set it up 1. **Set up your adapter once**: Connect it from Garage → OBD II. Odo remembers it. 2. **Drive**: When a trip starts, by hand or automatically, Odo reconnects to the adapter and records. 3. **Open the trip**: Scroll to the OBD II Summary, or open Channel Replay to play the engine data back. Note: Only trips recorded with an adapter connected have engine data. Custom readings are shown live and aren’t saved with trips. ## Questions and answers ### Do I have to connect the OBD2 adapter before every trip? No. After you set it up once in Garage → OBD II, Odo reconnects to the adapter whenever a trip starts, whether you start it by hand or automatically. ### How often does Odo record engine data during a trip? Every second. RPM, throttle, engine load and absolute load are recorded each second for Channel Replay, and each trip also saves an OBD II Summary with maximums, minimums and averages. ### How does Odo work out fuel used if my car doesn't report fuel rate? It estimates fuel from the engine's airflow (mass air flow), except on diesels. It then prices the trip from your last fill-up before it in your fuel log. ### Will a trip show if the check engine light came on while I was driving? Yes. If the check-engine light comes on or a new trouble code appears during a drive, the trip records it. ### Does Odo record OBD2 data during trips? Yes. Once your adapter is set up, Odo reconnects to it when a trip starts. The trip then saves an OBD II Summary: RPM, engine load, throttle, coolant and oil temperature, airflow, peak boost, engine-on time, fuel used with an estimated cost, check-engine events and any new fault codes. RPM, throttle, engine load and absolute load are also recorded every second, and Channel Replay plays them back in sync with speed, elevation and G-force. Electric cars can record the state of charge at the start and end of each trip after you add the battery reading from Presets. Custom readings are shown live and aren't saved with trips. More at /features/obd2-trip-recording. ### Does my OBD2 data sync with iCloud? Yes. Odo syncs your OBD2 data with the rest of your data through your private iCloud account: each trip's engine summary and its second-by-second engine recording, your custom readings, and each vehicle's engine data, including its trouble code history. The adapter pairing stays on the device, so on a new iPhone you connect the adapter once from Garage → OBD II. More at /features/icloud-sync-backup. ### Can I export my OBD2 data? Yes, in several ways. For all your trips, go to Settings → Data & Sync → Data Management → Export Data and choose Export as CSV or Export as PDF under OBD Data. Filters let you pick dates, vehicles and more first. For one trip, open its share menu and choose OBD Data for a summary as CSV or PDF, or All Data (CSV) with every second of speed, RPM, throttle, engine load, G-force, elevation and position. The Codes tab on the OBD II screen creates a diagnostic report PDF for your mechanic, and the Export Vehicle Data action in Shortcuts saves each vehicle as a JSON file. More at /features/obd2-data-export. ## Related - [Export OBD2 data](https://speedometerproapp.com/features/obd2-data-export): Trip engine data as CSV or PDF, a diagnostic report and a Shortcuts action. - [Route replay and analysis](https://speedometerproapp.com/features/route-replay): 3D route playback, replay videos, speed-colored routes, braking and G-force, stats and comparisons. - [Fuel tracker](https://speedometerproapp.com/features/fuel-tracker): Scan the pump, auto-pick the station and get accurate full-to-full economy.