If you are looking to improve your car’s performance or fuel efficiency you have probably come across engine remapping. But you may be asking yourself is remapping a car legal in the UK? The simple answer is yes but there are some important factors to consider before you proceed.
This guide will walk you through the legality of car remapping in the UK. We will cover everything from the process itself to the important considerations like insurance warranties and MOT requirements.
What is Car Remapping?
Before we look at the legality let’s clarify what car remapping is. Every modern car has an Engine Control Unit or ECU. This small computer acts as the brain of the engine controlling parameters like fuel injection ignition timing and turbocharger pressure.
Manufacturers typically set these parameters conservatively to cater for a wide range of driving conditions, climates and fuel qualities.
ECU remapping, sometimes known as engine tuning, involves modifying this software to optimise the engine’s performance. A specialist technician will connect to the car’s ECU through the OBD (On-Board Diagnostics) port and overwrite the standard software with new custom software. This new map can be tailored to increase power, improve fuel economy or provide a blend of both.
Is Remapping a Car Legal in the UK?
Remapping your car’s ECU is perfectly legal in the UK. There is no law that prevents you from modifying your car’s software. However the legality depends on how the remap is performed and how it affects other aspects of your vehicle ownership.
The key is that the modifications must not take your vehicle outside of the legal requirements for road use. This primarily relates to emissions. Any remap that involves tampering with or removing emissions control devices like a Diesel Particulate Filter (DPF) or Gasoline Particulate Filter (GPF) is illegal for road use.
So while the act of remapping is legal the consequences of a poorly executed or irresponsible remap can lead to legal issues.
Notifying Your Insurance Company About a Remap
This is the most critical point to understand. When you remap your car you are modifying your vehicle from its factory specification. All car insurance policies require you to declare any modifications to your vehicle. A remap is considered a significant modification because it alters the car’s performance.
Failure to inform your insurance provider about a remap will likely invalidate your policy. This means that if you are involved in an accident your insurer could refuse to pay out for any claims leaving you with a huge bill.
While some drivers worry that their premiums will increase this is not always the case. Many mainstream insurers and specialist providers are happy to cover remapped vehicles. It is vital to be honest with them from the start.
Will an Engine Remap Void Your Car’s Warranty?
Modifying your car’s software will almost certainly affect your manufacturer’s warranty. If you have a new or nearly new car still covered by its original warranty the manufacturer is within their rights to void the warranty on the engine and drivetrain components if they detect a remap.
They may argue that the increased power and torque places additional strain on parts that they were not designed to handle.
They may argue that the increased power and torque places additional strain on parts that they were not designed to handle.
This is a valid concern, but it should not deter you from improving your vehicle. Reputable tuning companies like VIEZU understand this risk. That is why we provide a multi-layered support package designed to give you complete confidence and protection.
VIEZU’s Protection Package: Our Commitment to Your Peace of Mind
Modifying your car’s software will almost certainly affect your manufacturer’s warranty. If you have a new or nearly new car still covered by its original warranty, the manufacturer is within their rights to void the warranty on the engine and drivetrain components if they detect a remap. They may argue that the increased power and torque places additional strain on parts that they were not designed to handle.
This is a valid concern, but it should not deter you from improving your vehicle. Reputable tuning companies like VIEZU understand this risk. That is why we provide a multi-layered support package designed to give you complete confidence and protection.
Lifetime Software Guarantee
We are so confident in our tuning software that we guarantee it for life. In the event that your tuning file is ever lost or overwritten during a dealer service, we will reinstall it for you free of charge for as long as you own the vehicle. This ensures your investment is protected for the long term.
30-Day Money-Back Guarantee
Your satisfaction is our priority. We offer a comprehensive 30-day money-back guarantee. If you are not completely happy with the remap for any reason, we will revert your vehicle to its standard factory software and provide a full refund. Please note that while the cost of the remap is fully refunded, any associated dyno testing costs are non-refundable.
Comprehensive Tuning File Insurance
For ultimate peace of mind, VIEZU also provides robust tuning file insurance. This policy is designed to protect you in the unlikely event of a component failure.
What it covers
Our insurance covers mechanical damage that is proven to be a direct result of a fault within the VIEZU tuning software itself.
Coverage Limits
This policy protects against repair costs for insured parts, providing a safety net against unforeseen issues.
Policy Duration & Restrictions
This is where our commitment truly shows. Our tuning file insurance comes with no mileage, no age and no time restrictions. This offers ongoing protection and support for the lifetime of your car’s tuning.
By choosing VIEZU, you are not just getting a remap; you are getting a lifetime of software support and the assurance that you are protected by a comprehensive insurance policy.
Car Remapping and UK MOT Emission Rules
Every car on UK roads must pass an annual MOT test to ensure it is roadworthy. A key part of this test is the emissions check which measures the level of pollutants your car produces which must comply with UK vehicle exhaust emissions standards.
A professionally conducted remap should not cause your car to fail its MOT. A quality remap optimises the engine’s combustion process which can sometimes lead to cleaner emissions. However a remap must not involve the removal of essential emissions hardware like the DPF. Removing these components is illegal and your car will instantly fail its MOT.
At VIEZU all our remaps are designed to keep your vehicle compliant while ensuring you stay on the right side of the law.
What are the Benefits of a Professional Car Remap?
When carried out by experts a car remap offers several benefits:
- Improved Performance: With performance tuning, you can expect a significant increase in horsepower and torque making your car feel more responsive and powerful.
- Better Fuel Economy: With economy tuning, especially on diesel engines optimising the engine software can lead to noticeable improvements in fuel consumption.
- Enhanced Drivability: A remap can smooth out flat spots in the power delivery making for a more enjoyable and engaging driving experience.
- Towing Made Easier: The extra torque gained from a remap makes towing trailers or caravans much easier.
Why Choose VIEZU
Choosing the right company for your remap is essential. VIEZU has been in the performance tuning industry for over 15 years. Our team of software engineers develops all our tuning files in-house ensuring the highest quality and safety standards.
We have a global network of over 600 dealers and our files have been used on more than 500,000 vehicles worldwide. We stand by our work with a 30-day money-back guarantee and our comprehensive insurance-backed warranty. Our commitment to quality and customer service has been recognised with a Queen’s Award for Enterprise. When you choose VIEZU you are choosing a trusted and experienced partner.
Frequently Asked Questions
Is an ECU remap safe for my vehicle?
Yes when performed by a reputable company. A professional remap operates within the safe tolerance limits of your vehicle’s components. At VIEZU we conduct extensive testing to ensure all our software is reliable and safe for your engine.
Can a car remap be reversed?
Yes, all our remaps can be reversed. We always save a copy of your car’s original software. If you ever want to return your vehicle to its factory settings we can do this for you.
How long does the remapping process take?
Most remapping can be completed within a couple of hours. The process involves a vehicle health check reading the original software modifying it and then writing the new software to the ECU. You are also welcome to wait in our comfortable waiting area.
About The Author
Paul Busby is the CEO of VIEZU Technologies Ltd. He is an experienced vehicle engineer who has specialised in post-production defect investigation and new vehicle homologation. His expertise in business development at a manufacturer level has been instrumental in VIEZU’s growth. Paul’s leadership and innovation were recognised when he won the Entrepreneur of the Year award in 2012 and when VIEZU received The Queens Award in 2014.
