Car remapping – is it worth it and will it work for me?

Remapping your car’s engine can improve its economy and performance. But a bad remap can heighten its unreliability as well as the cost of its insurance. Is a remap worth it? And how much should you spend?

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What are the engine remap risks?

A cheap remap can highlight existing problems with your engine. A rubbish remap will increase wear and tear on the components like brakes and clutch to an unacceptable level – and heighten the risk of you being left unexpectedly on the hard shoulder.

A bad remap can also:

  • Reduce the value of your vehicle

  • Void its warranty

  • Invalidate your lease contract if your car’s leased

All in, not great news.

What are the benefits of a good remap?

There are several improvement a remap can bring: better performance and fuel economy. Most modern cars can be ‘mapped’ whether they’re diesel or petrol. Done with care a remap is generally safe as a responsible specialist will ensure any ‘mods’ take place well within your car’s performance parameters.

A good quality remap can:

  • Cut your fuel bill and CO2 footprint

  • Give you more overtaking power

  • Sharpen your car’s efficiency and driveability

How much money should I spend to get it right?

A good quality remap costs anything between £250-£400. Pay attention to the reputation and credibility of your supplier. Many remap specialists will have certification from The Institute of the Motor Industry. That means they are more likely to use the latest software subscription updates and rely on good quality tuning equipment. 

Word-of-mouth recommendation can also be good. However a decent remap will always be a bespoke modification, designed specifically for your car, not ‘off the peg’. 

A good quality supplier will often offer a lifetime software warranty. 

Will a remap hit my car insurance costs?

Your insurance will almost certainly be effected, especially if you’re a younger driver or you’ve got a conviction. You have an obligation to let your insurer know if you’ve made any changes to your car. The remap or ‘modding’ industry has become much more mainstream during the last 20 years. Which means it’s seen as less risky by insurers, provided the job is done well. 

Which also means premium hikes are generally reasonable. But some insurers will not cover you if you remap your vehicle. So check first. 


  • If you don’t tell your insurer you will invalidate your policy

  • If you’re determined to go ahead with a remap and your insurer won’t cover you, approach the many remap specialist insurance providers 

  • As part of the online underwriting process you may be asked if your vehicle has been remapped – don’t hold back

What does engine remapping do to a car, exactly?

In the same way TV shampoo and conditioner ads promise extra shine and control, a remap company promise more go and economy from your existing car, for a price. 

The extra performance kick comes from changes made to a car’s engine control unit, known as the ECU. When your car left the factory it always had the potential to go faster and return better fuel economy. But car makers can’t tweak an engine for every market’s optimum atmospheric conditions. It’s too expensive. 

Car makers also put a high priority on the longevity of their vehicles. So car manufacturers, sensibly, create a middle ‘de-tuned’ ground, opening the door for engineering technicians – aka the remap market – to exploit the space in-between. 

Specifically, a remap will:

  • Change the fuel pressure and injection timings helping performance

  • Help you cover the ground faster with less effort

  • Potentially deliver better overall fuel economy

Can insurers tell if my own car’s had a remap?

No insurer is clairvoyant. Most insurers won’t demand a full probe of what’s under the bonnet for most minor accidents. But driving a ‘chipped’ car without telling your insurer remains high risk behaviour.

So play it safe

  • Declare – you may well be surprised at how mild the insurance increase is

  • By shopping around you might even reduce your insurance quote – sometimes it pays to be ‘peak sensible’

  • Some insurers take advantage of social media platforms and artificial intelligence to ‘cross-check’ suspicious behaviour

Also, when you declare your modifications you should also be covered for any accidental damage the modifications suffer. It makes it harder for an insurer to say No to a legitimate claim. 

What about car warranties – does a remap invalidate it?

It generally does. A remap exerts more power and strain on a vehicle’s drivetrain and no manufacturer can reasonably be responsible for that action. If the car is leased you are heightening risk again. Altering the engine’s performance could lead to a claim of devaluation. 

Also, why spend money on a car that, for all intents and purposes, you’re renting? A leased vehicle, remember, remains the property of the finance funder. So read the lease contract very carefully if you’re tempted, as well as give some thought to the health of your credit card.    

Bottom line: if a car goes faster it becomes higher risk for the party responsible for a) its manufacturing integrity or b) its legal cover. Most cars have got quite a bit more quicker and more economical in the last 10 years. So think, do you really need that remap, especially if it’s an extreme one?   

Is remapping a car 100% safe? 

That depends on how much or little you wish to spend and what condition your vehicle is in. Generally if you spend peanuts you get nuts. A garage mechanic or DIY-er working off an e-Bay CD will almost certainly be bypassing existing manufacturer engine updates your car might already have. 

Bear in mind:

  • Low quality remaps cost you time, expense and stress if your car’s ECU – your car’s brain – is inadvertently immobilised. Or the software is crawling with bugs. Or your car keeps defaulting to ‘limp mode’

  • Give some thought to your car’s condition. If there’s existing engine issues a remap may highlight these further, even if you spend your cash responsibly

  • Far better to spend money sorting the issue if there are problems. Or replace the car entirely if you can afford to

Good quality remaps, on the other hand, should pose few safety or reliability issues if carried out responsibly on a well-maintained vehicle

How do I know my car isn’t already chipped or remapped?

Is your car suspiciously frisky? Does it emit clouds of black soot under hard acceleration? Is the engine management light permanently lit? Frankly it can be difficult to tell if a vehicle has been ‘done’. 

You might check your car’s ECU (go online to find out where it’s located). Some re-mappers leave a sticker on the ‘black box’ to advise of any changes, though many won’t. 

Another reasonable option is to ask your local garage to check, using a diagnostic tool. Has there been any tampering, visible or otherwise? If you bought your vehicle through an approved used warranty scheme the garage will be obliged to make close checks before it sells the car on – though not every dealer will check every car ECU pre-sale. 

You have no such protection if you bought your used car privately.

Is chipping an engine the same as remapping one?

Up to a point. The word ‘chipping’ belongs to a time – specifically the 1980s and 1990s – when tuning boxes were often bolted to the inside of an engine bay, or larger engines simply shoehorned in. Think stripes, spoilers and bad boy cheap thrills. 

However, car remapping or ‘chipping’ has had a makeover. Modern engine tolerances are far more precise as technology and algorithmic computing power has soared. With less room for a bolt-on lash-up job and more need for deeper engineering skill, particularly on the computing side, the industry has evolved.

Which means smarter business premises, closer industry scrutiny and higher standards. Mankind just can’t stop fiddling.

Car insurance is just one of the costs of keeping your car on the road along with tax, petrol and servicing, so cut your insurance costs by comparing the best deals for you.

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