Chipping your car – a guide to engine performance chips and ECU remapping

If you've ever wished for a faster or more economical car but been put off by the cost, you're not alone. A new car definitely isn't cheap but did you know you can get that extra performance, efficiency or both for a lot less by 'chipping' the car you've got?

A car performance chip or a little engine ECU remapping can have startling results. It's easy and it's comparatively cheap but should you do it?

The very idea of tuning your car comes with a certain amount of baggage. It conjures images of boy racers with anti-social exhausts on their elderly superminis or DIY mechanics with bits of oily metal strewn across their kitchen tables.

The reality is that car tuning is far more commonplace than you'd think and it's growing in popularity among people who'd never consider themselves petrolheads. The latest technology can boost a car after just a few minutes plugged into a laptop and in most cases, you'll never guess who's had it done - until they put their foot down.

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What is car tuning?

Squeezing extra performance out of your car was once an arcane business. Doing so typically involved making mechanical changes to the engine by replacing standard parts with high-performance ones. Great fun if you're that way inclined but tricky and somewhat risky if you don't know one end of a spanner from the other.

Then computers came along to revolutionise the car world. In the 1980s Manufacturers began using microchips to control the way car engines performed. These in-car engine management systems are programmed to balance the sometimes conflicting needs for performance, fuel economy, long service intervals and reliability.

Today, the vast majority of cars on the road have an ECU or Engine Control Unit at their heart and by changing the parameters of these computers it's possible to improve a car's power, torque, throttle response, fuel economy and in some cases, all of them at once.

This can usually be done in a matter of minutes by plugging in a replacement microchip or directly altering the ECU's software with a laptop connected into the car's diagnostic port.

You can still go faster by fitting a performance exhaust system or a higher specification turbo to a modern car but it's an expensive business for the gains available. For most people, getting their car chipped by a man with a laptop and no oil under his finger nails is a far more attractive prospect.

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The low-down on chipping

The term 'chipping' comes from the early days of computerised car tuning when a replacement microchip would literally be plugged into a car's ECU to alter the engine's behaviour. Today, the term 'remapping' is more apt for the sophisticated tuning procedures that the leading companies perform.

A remap is all about adjusting the engine management software so there are no physical changes to the car itself. It's even possible to buy handheld units that plug into the car and allow owners to alter the ECU settings themselves, choosing a high performance mode when they feel like it, an economy optimised map if they don't or reverting to the factory settings.

Less advanced plugin chips that adjust the ECU map but can be physically removed when the extra performance isn't called for are also available. The effect of all these systems is similar to the Sport buttons that many manufacturers now fit to their quicker models but these rarely give an actual power increase in the way that a chip or remap can.

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How big are the potential benefits?

So, the big question: How much better could your car get with the aid of a chip?

You'll see some eye-catching claims by chipping technology companies about their ability to improve an engine's performance. Exactly how much extra oomph they'll be able to dial in, however, depends on the type of car.

Superchips technical director Jamie Turvey is in no doubt which models will benefit most. "Turbocharged cars give us the best results because we can pump more air in. With normally aspirated engines we have to tune them and there's less room for improvement.

"If the manufacturer offers versions of your car's engine with higher power outputs that's a good sign that we'll be able to increase its performance significantly. With the most powerful version of an engine, there's less to work with but we can still make gains."

As a guide, Superchips says it can boost power by up to 10% on a normally aspirated petrol car. Meanwhile, owners of turbocharged petrol models can expect an increase of anything up to 20% and diesels get the biggest shot in the arm with up to 30% on the cards.

Beyond those ballpark figures, the company's website has specific data based on the results they've achieved when working on particular makes and models. A quick search reveals that a Volkswagen Golf mk6 with a 110hp 2.0-litre TDI diesel engine could gain 38hp and 47lb ft of torque. The price for that is a not unreasonable £455. It's worth remembering that Volkswagen sold a 140hp version of the same engine but asked over £2,000 for the upgrade.

Could you save fuel too?

Some of the cost of a chip could even be offset by an improvement in fuel economy - a happy side effect that often accompanies chipping modifications on turbo diesel cars.

Superchips says its performance technology can bring fuel economy savings of up to 7% on diesel models and it has anecdotal evidence of small improvements on petrol cars too. Bigger gains are available elsewhere from firms that specialise in remaps designed to boost efficiency. These products use similar ECU parameters to those found in official eco-special models offered by manufacturers like Volkswagen's BlueMotion range and ECOnetic Fords.

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You have been warned (or you're about to be)

It might seem like you can't lose with an engine remap but your car's manufacturer might not see it that way and nor may your insurance company.

If you have any kind of modification work done on the car you'll definitely be obliged to inform your insurer and there's a good chance that your premium will rise as a result. Car tuning providers will often point customers in the direction of insurance companies that look more favourably on modified cars but a cost increase is still likely.

The car manufacturers are more concerned about their warranty cover. The official line from Volkswagen, whose heavily turbocharged engine range is a particular favourite with the car tuners, is that: "Non-approved power enhancement and / or chip tuning is not recommended and may result in the vehicle warranty being compromised or revoked on part failures related to these enhancements."

In response, the chipping companies point out that they work on large numbers of vehicles, many of them still under manufacturer warranty, and disputes are rare.

Superchips and the car chipping industry's other major names provide a back-up warranty of their own that's designed to fill any gaps in manufacturer cover relating to the chip and related parts. Many also claim that once installed, their chipping technology can't be detected by staff in service centres making warranty problems even less likely to arise.

Get a warranty quote for your car - from £15 per month

Could your car's reliability be affected?

The warranty cover may be as good as its word but many people considering chipping their car won't even have one. A more pressing concern for them will be the effect on reliability and whether a chip could take years off their car's life?

The manufacturers clearly advise against owners modifying cars like this. They would say that buffer zones are deliberately designed into their products to ensure longevity and a remap removes these but Superchips' Jamie Turvey mounts a strong defence:

"They would definitely say that but when car manufacturers develop an engine they plan to incrementally increase its power and performance over its lifecycle. The capacity for more performance is built into the engine from day one so we aren't threatening the car's longevity by accessing it for our customers. We never tune a car beyond what the engine can comfortably take."

At the high-performance end of the market Superchips is also emphasises the importance of improving the car as a whole rather than simply throwing more power at it.

"When manufacturers increase the power of their engines they often upgrade suspension, brake and steering components to cope and we would always advise our customers to this effect. If a customer wants to exceed the top power output offered by a manufacturer on a particular engine, we would advise them to make other improvements to ensure they can get the most from the car."

Despite the apparent conflict between manufacturers and modifiers, it's not unheard of for them to work together. Superchips has shared the data it collects with car firms and has even provided remap solutions that have been adopted to help new models perform better.

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Should you chip your car?

Car modification was once a pastime for committed petrolheads with a bit too much time on their hands but the advent of computer engine remapping sent it mainstream.

The process is no longer seen as a dark art and ordinary motorists are increasingly turning to chipping as a route to extra hustle with minimum hassle and expense. As long as you keep your insurance company in the picture, there's no real reason why you shouldn't too.

Have you had your car chipped? Are you considering it? Let us know your thoughts in the comments section below...

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