A driveway remap – sometimes called a generic remap or a plug-and-flash tune – involves a tuner connecting a laptop to your car's OBD port and writing a pre-written file onto your ECU. The entire process typically takes 15–30 minutes.
That file has been written on someone else's car, in different conditions, with different fuel, at a different ambient temperature – and it's being applied to your vehicle with no testing, no data logging and no verification whatsoever.
There is no dyno. There are no power figures. There is no before and after comparison. The tuner has no idea how much power your car is actually making, whether the fuelling is safe, whether the boost pressures are within limits, or whether the tune is causing any stress to the drivetrain.
For many cars on a standard tune, a generic file may appear to work without issue – initially. But the risks are real, particularly on modified vehicles, vehicles with high mileage, or engines with any existing wear.
