Remap or Tuning Box for More Power and Better Fuel Economy

Today’s engines are run by computer. The ECU (engine control unit) makes thousands of decisions per second about fuelling, how much air to supply, how much turbo to use etc., affecting the power and economy of your engine. For many reasons including marketing, poor fuel quality in some parts of the world (and poor maintenance), manufacturers ‘de-tune’ your engine before it even leaves the factory, meaning 99% of us never get the performance or the economy our engines are truly capable of. You will notice this when you’re driving and you get ‘flat spots’ or lack of responsiveness when you pull out to overtake, or when you struggle up hills or round sharp bends.

A remap (chip tuning) or a tuning box can release the power and economy that are built in but repressed by the manufacturer.


A ‘remap’ is a replacement program for the ECU. It can change all of the instructions that determine the way your engine runs. Remapping can be applied to petrol engines and diesel engines, though it is most effective on turbo-diesels and turbo petrol engines. The average turbo-diesel can expect a gain of 30hp to 50hp as well as up to 20% more torque. It is common for this extra power to actually deliver MPG improvements; typically around 5% to 10%, but in the case of some commercial vehicles up to 20% is not unheard of. Many drivers get an extra 50 miles or more per tank of fuel. Most modern vehicles can be remapped in an hour or two through the diagnostic port inside the car.

Tuning Box

A Tuning Box can only be used with diesel engines. A tuning box modifies only the fuelling. So why would you choose a tuning box? A tuning box is still a very effective way of improving MPG and power, and may be the only option because a remap is not possible or practical for a particular vehicle. It will still give you significant improvements over the original tuning, and is a practical and effective way of cutting your overall motoring costs and improving your driving enjoyment. Tuning boxes can be fitted by the vehicle owner or by an installer if you are not confident.

How can I get better MPG while I also get more power?

Optimum MPG comes from engine efficiency. When an engine is de-tuned by the manufacturer for the reasons stated above, we suffer the consequences.

More power allows you to drive more efficiently. You already know that revving the engine hard will waste fuel, and that driving up hill in low gear isn’t fuel-efficient. It therefore makes sense that if you’re getting more power from the same engine, and you can change into higher gears faster, or stay in higher gears for longer, you save fuel compared to when you were working your engine harder to do the same thing.

Remap or Tuning box? The choice is now yours.

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