Tachwire

Tachwire reads your BMW through a Bluetooth LE OBD adapter and shows what the car usually keeps to itself: gearbox, oil and coolant temperatures, oil pressure, boost and gear — and on a plug-in hybrid the electric motor and the high-voltage battery. On the car's screen as CarPlay tiles, on the Lock Screen as a Live Activity, and out loud when something runs critically hot. IN THE CAR • CarPlay tiles you arrange on the phone: up to four screens, as many tiles in a row as your car's display has room for. They are Apple's CarPlay templates, redrawn twice a second — a screen of tiles, not a drawn gauge cluster. • A Live Activity on the Lock Screen and in the Dynamic Island; on iOS 26 also in the CarPlay Dashboard beside the map. • Spoken warnings, the way navigation speaks: oil pressure dropping, oil, coolant or gearbox critically hot, the tank or the battery nearly empty. The voice is generated on the phone and speaks 10 of the app's 11 languages (Chinese not yet). • Cold, ready, hot: a scale that is blue while cold, green in range, amber when hot and red when critical. The warm-up counts down to READY. WHAT IT READS • Standard OBD readings plus the BMW modules themselves: the gearbox for its temperature, a hybrid's e-motor and high-voltage battery, a diesel's particulate filter. The car is recognised from its VIN. • Power from the torque the engine reports, minus the friction of your own car, learned as you drive. Until that is proven the figure is dimmed and kept out of records. No estimates. • Ignition retard under load, and intercooler efficiency where the engine reports the temperatures around it. • Plug-in hybrid: engine, e-motor or both, battery current, regeneration and the electric share of every drive. AFTER THE DRIVE • Every drive on one page: the route, events, charts of dynamics, power, temperatures and the gearbox, g-forces, and the fuel or kWh it took. • Runs: 0–100 and 100–200 km/h or 0–60 and 60–130 mph, the ¼, ½ and 1 mile, timed from the car's speed. With a Dragy connected, the Dragy times the run. • Laps against a start/finish line you set. Trends over a week, a month or a year. Records count only full-throttle pulls. Runs and laps belong on a closed track. WHICH CARS Driven with the app so far: X5 xDrive45e, X5 xDrive40i and X6 xDrive40i — everything the profile reads; X6 xDrive40d and F15 X5 xDrive25d — partly. Recognised from the VIN: the G-series from 2018 (petrol, diesel, plug-in hybrid, electric), the F15 X5, F16 X6, X5 M and X6 M. On a car we have not seen yet some readings may be missing: the tile stays empty rather than show a wrong number. The full list, reading by reading, is at tachwire.app/cars. Tachwire is new, and it learns new cars from the drive logs owners choose to send under More → Help the project. WHAT YOU NEED • A Bluetooth LE OBD adapter. Driven on: OBDLink CX (the fastest), vLinker MC+, vLinker BM+, UniCarScan UCSI-2100. Classic Bluetooth and Wi-Fi adapters cannot connect to an iPhone. • CarPlay, wired or wireless: the app reads the car only while CarPlay is connected. iOS 18 or later; tile cards in CarPlay need iOS 26, earlier versions show the same readings as a list. • No car nearby? Choose "No adapter yet — try the demo" and look around every screen on simulated data. READ-ONLY Tachwire only reads live values while you drive. It does not read or clear fault codes, code the car or change anything in it. PRIVACY No account, no ads, no tracking. Drives stay on the phone unless you turn sending on (encrypted, route removed). Crash reports are on and turn off with one switch; usage data only if you agree. Tachwire is an independent app, not affiliated with or endorsed by BMW AG or Dragy. BMW, CarPlay and Dragy are trademarks of their owners.