Explained: What Is ECU (Engine) Remapping?

When a car rolls off the production line and hits the market, you might think it’s in the best condition it will ever be in. For the most part, this is true, but even the brand-new engine might be packing more of a punch than the factory default settings allow it to unleash. Electronic Control Unit (ECU) remapping, often referred to as engine remapping or simply “tuning”, involves adapting the car’s software to allow its engine to reach maximum potential.

A car's engine

What Is ECU Remapping?

ECU remapping is more commonly known as car tuning (or ECU tuning) and involves overwriting the vehicle’s onboard software settings to allow customised options to be implemented. These options can manage settings like fuel injection, sensor operation and much more, though not everything can be altered legally.

How Does Remapping Work?

The process of remapping your car doesn’t involve too many steps and is actually fairly straightforward, as long as you know what you’re doing. Using the car’s onboard diagnostics port, a computer (typically a laptop brought into the garage) can be hooked up to the car to implement new software onto the ECU.

The new software will allow the car’s computers to bypass any limitations placed upon it by the manufacturer. Sometimes these are to fall in line with local legal restrictions, other times it’s to preserve the car itself and slow down the effects of wear and tear on any components that could result in you scrapping it earlier than expected.

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What Does ECU Remapping Do?

Remapping a car’s ECU can have a number of positive effects. First and foremost, the handling of the vehicle. Immediately noticeable the very first time you try to take a corner or accelerate from a standstill, the car will have much more power in the pedal. Essentially, you’re given better control over how the vehicle operates at speed.

Another significant consequence of remapping is fuel economy. There seems to be some conflict when discussing ECU remapping and its effect on the fuel economy of a vehicle. On one hand, it is possible to increase a car’s miles per gallon figures by carefully tweaking the amount of fuel that is burnt. However, others believe that the extra power that comes from tuning your car comes at the expense of fuel economy.

Either way, it’s safe to say that remapping could indeed have an impact on how much fuel your car uses. Economical driving can help counter this, but let’s be honest… if you’re getting your car remapped, you’re probably not planning to go light on the accelerator.

Does My Car Need Remapping?

This depends on how you intend to drive it. If you’re just using it to get safely from A to B and you’re not in a hurry, then no. If you’re using it to mostly drive through city centres or built-up areas packed with traffic, then no again.

If you’re using it for long distance motorway drives or winding, hilly country trips however, then you could benefit from an ECU remap. At the end of the day though, remapping is used to bring out the beast that’s hidden within your car… how often are you going to need that if you’re driving on public roads and abiding by the law?

Is ECU Remapping Legal?

While you may feel like a big-time hacker when altering the code on your car, there’s actually nothing illegal about it. Sure, you could end up taking your car’s noise and emission outputs above government limits which really could leave you in trouble with the law, but the only authorities that will really show concern are the manufacturers and your insurance company.

If you get your car’s engine remapped, your warranty will become void and your insurance premium may increase. Yes, you will need to inform them of the procedure, because if you don’t and attempt to make a claim, your policy could become void along with your manufacturer’s warranty.

Should You Remap Your Car’s ECU Yourself?

First of all, it’s not a good idea to attempt to remap your own car if you don’t know what you’re doing. It’s an incredibly technical procedure that needs to be performed by an experienced professional. Doing it wrong could turn a perfectly operational car into a glitchy mess running on dodgy code and force you to pay up for a reset. Secondly, it’s important to realise that not all cars can actually be remapped at all. The general rule of thumb is that if your car was produced pre-2000, it won’t be tuneable. Those cars would instead need their chips physically removed and altered before being re-soldered back into the vehicle, a service that many places won’t offer or would charge through the nose for.

Ultimately, attempting to remap your own car is probably a terrible idea and should be completely avoided unless you’re exceptionally brave or have money to burn in case of emergency repair requirements.

Is Car ECU Remapping Worth It?

This totally depends on what you’re planning to do with the vehicle once the procedure is complete. Going to continue using it in the same way, with short trips to the shops or to work and the occasional long-distance road trip? Then remapping is probably not something you’ll benefit from. However, if you require a car with top-notch performance and the ability to hit (and maintain) high speeds in a flash, then you might find some worth from tuning.

You’ll gain more power and better performance, it’s relatively cheap when compared to the price of the car itself at a few hundred pounds, and doesn’t require a huge amount of manual labour to strip the car to bits in the process. But, it will (probably) lower your average mpg rating, invalidate your warranty and could increase your insurance price, plus it’ll wear down your engine faster.

You need to weigh up your options, but at the end of the day, it’s a procedure that will take your car beyond the performance levels that British roads would ever realistically require. That’s another thing to consider when making your decision.

If not even a remap could bring your car up to speed with the vehicles around on the road, it might be time to offload it and get something new. Scrap Car Comparison can get you the best prices for your car in just 30 seconds and find you a local scrap buyer to come and take it off your hands. We’ll even sort out collection of your car for free! Try our scrap value calculator now to find out how much you could get from selling your scrap or salvage car with Scrap Car Comparison.

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