OBDII Car MPG Demo (Gasoline)

Monitor real-time fuel consumption on your OBD-II compliant gasoline vehicle with OBDII Car MPG Demo (Gasoline). This app connects your Android phone or tablet to your car's engine computer via a Bluetooth OBD-II adapter, automatically detecting your vehicle's protocol and displaying live MPG data alongside engine diagnostics.

To get started, you'll need an OBD-II compliant car, a Bluetooth ELM327 adapter or compatible equivalent, Android 4.1 or newer, and Bluetooth enabled on your device. Once paired, the app auto-detects which of four major OBD-II protocols your car uses—SAE J1850 PWM (Ford), SAE J1850 VPW (GM), ISO 9141-2 (Chrysler and imports), ISO 14320 KWP-2000, or ISO CAN 15765 (most post-2008 models)—so setup is straightforward.

The app calculates fuel consumption using your vehicle's supported parameters. If your car has a Mass Air Flow (MAF) sensor and reports Vehicle Speed (VSS)—which nearly all modern vehicles do—you'll get accurate MPG readings. For vehicles without MAF sensors, you can manually enter your engine displacement and volumetric efficiency to derive a synthetic MAF calculation using the Ideal Gas Law formula. The demo version lets you verify whether your car supports the necessary PIDs before committing.

The display features four small analog gauges showing real-time intake air temperature, mass air flow, manifold pressure, and vehicle speed. A large gauge dominates the center, displaying instant MPG. Below that, a data table tracks average MPG, fuel consumption in gallons and liters, and L/100km efficiency. Two odometers log miles and kilometers traveled, while a trip timer counts engine-run time. Fuel-type indicators show whether you're running gasoline or ethanol blends, and gallon units toggle between US and Imperial measurements.

You can customize engine displacement, volumetric efficiency, and fuel type in settings to match your specific vehicle. The app connects to real OBD-II adapters plugged into your car's diagnostic port, or optionally simulates data via the ECU Engine Pro app for testing without a vehicle.

OBDII Car MPG Demo (Gasoline) is designed for drivers who want direct access to their vehicle's fuel economy data without relying on manufacturer dashboards or third-party fuel tracking.