Volumetric efficiency

One WOT pull in 2nd or 3rd, low revs to high revs. The app locks MAF, RPM, MAP and IAT, then calculates cylinder fill against manifold air density. MAP versus baro on the pull tells it whether the engine is naturally aspirated or on boost — you do not set that yourself.

Use on the road at your own risk

You are responsible for the vehicle, passengers, other road users, and for obeying all traffic laws at all times.

Do not look at the screen while the vehicle is moving. Do not carry out wide-open-throttle pulls, logging, or any test unless the road is legal, clear, and safe, and you can keep full control.

Tests in traffic, near pedestrians, on wet or broken surfaces, or where speed limits or local rules forbid it, are on you — not this app.

Data-drive and its authors accept no responsibility or liability for accident, injury, death, vehicle damage, property damage, fines, lost data, or any other loss arising from use of this software or any OBD adapter, including if a reading is wrong, a feature fails, or the app distracts you. You use Data-drive entirely at your own risk.

I will obey the law. I use Data-drive at my own risk.

Registration

Make

Model

Displacement (litres)

Four-stroke only. Uses MAP for density, so turbo cars are measured against boost, not atmosphere. A MAF is preferred. With no MAF, air is taken from the wideband and the fuel rate when the ECU reports both.

1Engine up to temperature — coolant over 80°C.
2Only if it is legal and safe. Clear road, 2nd or 3rd, about 1,500–2,000 rpm. A passenger should watch the screen — not the driver.
3Floor it in one pull to high revs. Do not shift. Diesels: pin the pedal — we do not need a throttle plate.
4Lift when you are done. The app captures the WOT window on its own.