Engine remapping is one of the most effective ways to improve a car's performance without making mechanical changes to the engine. Whether you want more power, more torque or better fuel economy, this guide covers everything you need to know before you book a remap.
What is engine remapping?
Engine remapping, also known as chiptuning or ECU tuning, means changing the software settings of your car's engine control unit (ECU). The ECU manages fuel injection, turbo boost pressure, ignition timing and many other parameters.
Manufacturers program the ECU with generous safety margins to allow for variations in fuel quality, extreme climates and long service intervals. A remap uses some of that headroom to unlock the engine's hidden potential.
How does a remap work?
The process takes place in several steps. The tuner starts by reading the original software (the "map") from the ECU through the car's OBD2 port. They then analyse the parameters and adjust the data tables (maps) to optimise performance. Finally, the new map is written back to the ECU.
Factory map
- Conservative safety margins
- Generic settings for every market
- Power restricted in software
- Fuel economy not optimised
After a remap
- Settings optimised for the fuel you use
- Smoother, more linear torque curve
- Power released within mechanical limits
- Potentially lower fuel consumption
Typical remapping gains: power, torque and economy
Gains vary considerably depending on the type of engine, its size and whether it has a turbocharger. Turbocharged engines offer by far the best potential.
Typical power gain on a turbo diesel engine (for example 150 hp to 190 hp)
Typical torque gain, felt from low revs for stronger in-gear acceleration
Possible reduction in fuel consumption thanks to better engine efficiency
Naturally aspirated engines (without a turbo) offer more modest gains, generally between 5% and 10%. Remapping really comes into its own on turbocharged engines. To understand the different levels of tuning, read our guide to Stage 1 vs Stage 2 remaps.
Remapping risks: warranty, insurance and reliability
Like any modification, remapping carries risks that you should understand and weigh up before going ahead.
- The manufacturer's warranty may be affected if a software modification is detected
- A badly executed remap can damage the engine or the turbo
- A remap is a modification that must be declared to your insurer, and failing to do so can put your cover at risk
- A reputable tuner works within the engine's mechanical limits
- The original map is saved and can be restored
- Many tuners offer their own warranty on the work
How to choose a remapping specialist
Choosing the right tuner is the most important step. A good professional has the right equipment, knows the specifics of your engine and works with custom remap files rather than generic ones.
- Check their experience and customer reviews
- Ask whether they have a rolling road (dyno) to verify the results
- Make sure they offer a warranty on the work
- Choose a tuner who saves your original map
Use the ChiptuneMAP directory to find a trusted remapping specialist near you, with their contact details and customer reviews. You can also learn more about engine remapping on our dedicated page.
Chiptune Team
Specialists in digital solutions for automotive engine remapping.