FixMyCar explains what remapping is and how it could benefit your car.
Compare remapping quotesEllie Dyer-Brown
Monday August 11 2025
6 min read
Car remapping - more commonly known as engine remapping - is a cost-effective way of tuning your vehicle to deliver a range of potential benefits. If you have questions about how remapping works, how much it costs, and the advantages and disadvantages it can bring, this guide is for you.
Every car has an onboard computer called the engine control unit (ECU). You can read about what it does here. Most of the time, the ECU is factory programmed in a way that limits a car’s performance to optimise fuel efficiency, emissions and reliability. Engine remapping is the process of modifying the ECU to change its behaviour.
An engine remap involves writing a new software programme onto the ECU. This process is done by plugging a laptop into the car’s OBD port, which is the same plug garages use to diagnose car faults.
You can’t just plug your car into your laptop and expect brilliant results - it’s a job best left to the professionals. That said, some companies offer a DIY service.
The new software will optimise the engine’s behaviour to achieve your desired results.
A remap can significantly boost your car’s performance - though extra power isn’t the only reason for doing it. You can also do a fuel efficiency-focused remap to get more miles for your money.
Typically, a remap works by optimising:
Ignition timing
Fuel injection
Air/fuel ratio
Accelerator response
Turbocharger boost
A stage one remap is the most basic form of engine tuning. It involves a software upgrade to change the output of the engine.
The second stage of remapping, which involves another software update, provides significant power gains. You can expect an increase of around 30-50%. However, it's important to note that your car must have a turbocharger or an intercooler for a stage two remap, as these components are essential for handling the increased power.
Find out how a turbocharger works in this guide.
The third remapping stage unlocks even more power, resulting in gains of over 50%. It should only be carried out by trained professionals because it involves significant modifications to the turbocharger, engine and intercooler.
The advantages of remapping are as follows:
Affordable - remapping is one of the least expensive ways of boosting your car’s performance.
No physical upgrades - you don’t have to change any physical aspects of your vehicle.
Usually reversible - most of the time, you can reverse a remap and reinstall your car's original software.
I have had most of my vehicles remapped. As long as your car is well maintained and there are no issues beforehand, it’s a great option to get the most out of your vehicle. But make sure you choose a reputable company with great reviews. Any car still under warranty shouldn’t be remapped as it could void the agreement.
Matt Wrankmore
Head of FixMyCar's Garage Network
Remapping also comes with several potential downsides:
Invalidates warranty - usually invalidates your car's warranty, so you should proceed cautiously.
Higher insurance premium - you might pay more for your insurance.
Less reliability - the harder your engine works, the more likely it is to fail.
High-octane fuel - if you've boosted your car's power, you might have to use a pricier high-octane fuel.
It's important to note that the benefits of remapping are mainly seen in turbo engines. If your car doesn't have a turbo, it's unlikely to see a significant power increase from a single remap.
This guide explains why your car might be losing power.
Unfortunately, remapping your car will likely increase the price of your insurance. If you decide to proceed with a remap, you must inform your insurer, or your policy will be invalidated. It’s also worth considering that although remapping is growing in popularity, some insurance providers may refuse to cover a car that has been remapped.
Learn more about car insurance and how to get it cheaper.
According to our data, the average price of an engine remap is £243.27. That’s how much you can expect to pay for a stage one remap. As you go up the stages, remapping becomes more expensive. A stage two remap can cost around £1,000, while a stage three job could cost several thousand pounds.
Below is a table showing how average prices vary between manufacturers.
FixMyCar can help you find a trustworthy garage with remapping expertise. Enter your details to receive quotes straight to your inbox.
Remapping a car is legal in the UK. You must inform your insurance provider if you have remapped your car to avoid invalidating your insurance policy.
There’s no denying that remapping places more strain on your engine - especially if you’re looking to increase its power output. You must follow a regular maintenance schedule that accounts for this extra stress. Taking good care of your car is of utmost importance following a remap.
Remapping is done chiefly on turbo diesel engines because this is where it has the most significant benefit. However, most modern cars can be remapped, even if they run on petrol. It’s best to discuss with a professional whether your vehicle will benefit from remapping. Just because it could be remapped doesn’t necessarily mean it will be worth it.
You will usually need a car that was manufactured after 2000 to be able to remap it. Cars made before that year may not have the necessary technology.
Most people remap their cars to get more power from them. Generally, higher speeds and more power use more fuel, decreasing efficiency. It depends on what you target with the remap - it can be tailored specifically for better fuel economy rather than power.
They are different terms for modifying the car’s onboard computer. Essentially, they’re the same thing, although remapping uses the car’s diagnostic port, while chipping may involve removing and updating a physical chip.
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Ellie is FixMyCar's Content Manager. She has over three years of experience writing about cars and regularly collaborates with automotive experts to provide trustworthy advice for drivers that is easy understand. Her work has been featured in Yahoo! Finance, iNews, The Daily Express and The Sun. She has a BA in English literature and an MA in creative writing from Durham University. Outside of work, Ellie follows F1 and eagerly awaits Ferrari's next era of dominance in the sport. She drives a Suzuki Swift.
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