Engine remapping is a process, carried out by a qualified mechanic, where they modify a vehicle's Engine Control Unit (ECU) software to improve its performance and fuel efficiency.

The ECU is a small computer that controls various engine functions, including fuel injection, ignition timing, and turbo boost pressure. In higher spec vehicles, the ECU plays a crucial role in increasing performance.

By changing the ECU's parameters and limits, remapping can increase horsepower, torque, and 0-60mph speed times.

It does this by adjusting the fuel-to-air mix, along with timings and other performance variables. The result is faster acceleration and better throttle response. This is why remapping is often used in turbocharged engines.

In summary, remapping can be tailored to specific needs. For instance, some drivers prioritise high performance, while others might seek better fuel economy driving.