Engine remapping: What is it and does it work?

For decades motor enthusiasts have modified their cars. Whether it was altering the appearance of a vehicle such as installing a new body kit or boosting its performance by upgrading the car’s tyres for grip …

Engine Remapping

For decades motor enthusiasts have modified their cars. Whether it was altering the appearance of a vehicle such as installing a new body kit or boosting its performance by upgrading the car’s tyres for grip – people have found a way to customise their car to suit their needs.

Whilst car modifications have been a relatively underground phenomenon, we are seeing a surge in car tuning in recent years, particularly engine remapping.

Engine remapping is one of the most common modifications that can be made to a vehicle. This is primarily due to the ease at which it can be done and, thus, its low cost. But what is it? That’s what we’ll explore in this article.

We will describe what engine remapping is, how it can boost a vehicle’s performance, its benefits and limitations, and how much it can cost.

What is engine remapping?

Engine remapping, also known as ‘chipping’, is a process that improves a car’s performance by modifying the internal microchip in the Engine Control Unit (ECU). The ECU is where software regulating engine performance is installed. By overriding these settings, a car’s performance can be pushed to its ‘full potential’, resulting in more power.

Vehicles bought directly from the manufacturer or dealership are known as ‘stock vehicles’, meaning they come with factory settings. The manufacturer determines these settings and tends to limit performance in favour of complying with safety regulations, reliability, emissions laws, fuel efficiency, etc. Limiting the performance allows car makers to tailor their vehicles toward specific regulations, terrain and weather, which can prolong the vehicle’s life. It also enables them to use the same engine in high-performance models simply by altering the ECU software.

How does car engine remapping work?

Engine remapping works by overriding the car’s Engine Control Unit. It’s a small chip that acts like a computer for the engine. Before the year 2000, the ECU chip would have to be removed, retuned to allow for greater performance, and reinstalled into the engine. These days, it’s much more straightforward.

In modern vehicles, car engine remapping involves connecting a laptop to the onboard diagnostic (ODB) port. Mechanics and technicians use the car’s onboard diagnostic port to access the ECU, often using this method to troubleshoot and analyse engine problems. Once connected, though, it can also be used to engage in an engine remap by altering the performance settings.

It’s a straightforward process that can be completed in just a few minutes. That’s not to say anyone can do it. It’s not as simple as downloading and attempting to install the software at home. Any changes that are made will immediately improve the car’s performance capabilities, whether that’s with more power, emissions, noise, etc. Therefore, it will require the hand of a trained professional to ensure that adjustments are safe for the car and the driver.

Do I need to tell my insurance provider if my car is remapped?

Yes, your car insurance provider will have to be informed of any modifications to your vehicle, including engine remapping. Engine remapping will affect the car’s performance on the road and, therefore, how the car is driven – it no longer performs as a stock, factory-setting vehicle. This classifies the car as a specialist car, which means it will require specialist motor insurance. Your existing provider may increase your insurance premium for this, and you could be charged a policy change fee.

Not reporting remapped cars to the insurance provider will invalidate your policy. This means that the insurance policy will be void, and your vehicle will not be covered in the event of an accident. Suppose your existing provider does not insure vehicles with engine remapping. In that case, there are numerous specialist motor insurance providers and brokers who will be able to assist you in finding the best deal.

What are the benefits of engine remapping?

As mentioned earlier, the main benefit is that drivers can get extra power out of their engine, which will drastically affect the car’s speed and performance. However, there are various other benefits of car engine remapping:

Improved driveability

Improved engine response and power delivery may make the car easier to drive. It can enhance control, responsiveness, and ignition timing.

Better fuel economy

By remapping, you can increase the vehicle’s mile per gallon and overall fuel economy. If you are a driver who doesn’t rev the accelerator too much, you’ll be optimising how much fuel your vehicle burns. This can save you money in the long run and reduce your overall carbon footprint.


With most modern cars, engine remapping is a reversible process. In the same way, software was introduced to improve the engine’s performance, the manufacturer’s factory settings can be installed back in.

Physical upgrades are not necessary

Rather than buying and installing physical upgrades, like new tyres or even a new engine, remapping can be done without making any physical changes to the car. In fact, most upgraded parts will require an engine remap first in order to be utilised effectively.

Low cost

Engine remapping is one of the most affordable ways to improve a vehicle’s performance, with prices starting as low as a few hundred pounds.

What are the downsides of engine remapping?

As with most things, there are downsides to carrying out engine remapping. They include the following:

Voided warranty

When it comes to making a vehicle modification, car makers are incredibly selective of who they allow to do so. Engine remaps done by anyone but the manufacturer or approved dealerships will void the vehicle’s warranty. Your vehicle paperwork should have all the relevant information regarding this. It should be noted that once the warranty has been voided, reverting the engine performance back to factory settings will not validate the warranty again – a voided warranty cannot be reversed.

Increase the cost of car insurance

As with any alteration to a vehicle, you will have to inform your car insurance provider. If the insurance provider permits the engine remapping, they may increase your premiums in order to reflect the car’s new performance, as well as a policy change fee. Failure to notify the car insurer may void your policy, meaning if you are involved in an accident, they can refuse to payout towards damages.

Vehicle strain

Whilst your vehicle will benefit from better performance, it could suffer from reduced reliability. The increased power will put increased stress on not only the engine itself but the brakes, clutch, tyres and suspension. This could result in your car breaking down more often and requiring frequent visits to the repair shop.

Worse fuel economy

We listed improved fuel economy in the benefits section, so you may be asking why it’s listed as a downside. Well, it depends entirely on how you drive. With the improved engine power, it can be tempting to put the foot down and push the car to its limits. Driving like this will negatively impact your fuel consumption, and you may find yourself spending much more on fueling your petrol or diesel engine than usual.

Fuel type

Depending on your car and engine, an engine remap could result in you needing to buy higher octane fuel, which is usually more expensive.


When car manufacturers build their cars, engineers spend a great deal of time testing the vehicle on and off the road in various conditions. This ensures the car is safe enough to drive in different scenarios, such as extreme weather conditions. After an engine remap where the car’s performance has been altered, the safety of the vehicle and driver cannot be guaranteed since it’s difficult to predict how well the car will handle the same conditions.

How much does engine remapping cost?

There are three different stages to which you can remap your engine; the more extensive the upgrade, the more it will cost.

‘Stage 1’ remapping involves a slight performance boost. This is achieved by lightly reprogramming the engine management system of a car within the optimised parameters. This slight upgrade can provide the desired effects of remapping and can cost as little as a few hundred pounds.

‘Stage 2’ engine remapping builds on the previous stage by upgrading the exhaust and/or inlet. For diesel cars, a stage 2 upgrade will include modifying the exhaust. With petrol cars, a complete exhaust upgrade will be made alongside air intake modifications. This level of engine remapping can cost as little as £500 to around £1,000.

The final level of engine remapping is ‘Stage 3’. This is where heavy modifications are made to the engine, such as the addition of a turbocharger, rods, pistons, fuel pumps, etc. These upgrades will drastically improve a vehicle’s performance, including a noticeable horsepower boost, torque, and throttle response. But these upgrades will also require the upgrade of other components in order to cope with the extra power safely. As such, you can expect to pay more than £1000.


Can any car get its engine remapped?

Not all vehicles are eligible for engine remapping. Older cars, namely those that were manufactured before the 21st century, will be more challenging to remap compared to a new model. This is because older cars often require the entire chip to be modified instead of simply upgrading the software. This is done by removing the chip entirely and then resoldering it back into the vehicle.

What types of cars benefit most from engine remapping?

Cars with petrol engines can be remapped, however, the performance improvement may not be as great. The most significant benefit will be to cars with turbo diesel engines. These vehicles will provide the most value for your money when being remapped since they can manage such drastic performance boosts.

Where can I get my car engine remapped?

Most local car garages and repair shops will offer engine remapping as a service. However, it’s crucial to go with a reputable company. Since you’re affecting the performance of the car’s engine, its emissions, etc., these changes must still be within regulations set by law. If not, you may be driving an illegal vehicle. Reputable professionals will ensure that your engine remapping stays within legal limits, regardless of the stage of upgrades.

Additionally, you may have a modern car within its warranty period. In that case, you will want to go to the manufacturer or an approved dealership for the service to prevent voiding the warranty.

Will my car be more fuel-efficient if I get the engine remapped?

This depends entirely on how the car is being driven. If the vehicle is driven responsibly without revving the accelerator too much, you may find that your car becomes more fuel-efficient and requires fewer trips to the petrol station. On the other hand, if the newfound power is hard to resist and you find yourself pushing your foot down regularly, you will notice that the vehicle uses up considerably more fuel.

Is there an alternative to engine remapping?

Tuning boxes are a suitable alternative to engine remapping. Also known as ‘engine chip tuning boxes’, they work by misleading the ECU. It tricks the ECU into adding more volume of fuel into the cylinders. This creates a surge in pressure, which translates to more power and torque for the vehicle.

Because tuning boxes are plugged directly into the engine’s electronic control unit – without altering the car’s factory settings – they can be easily installed and removed without hassle. The ease at which they can be implemented makes them a cheaper alternative to engine remapping. It is also possible to install the tuning box yourself at home. However, it is recommended to visit a professional. As with engine remapping, the same downsides apply to chip tuning boxes.