All modern cars and vans on the road today have an ECU(ENGINE CONTROL UNIT). This Engine Control Unit can almost be described as the vehicles ‘brain’ and contains a small processor that takes information from various sensors throughout the engine. It analyses information such as the engine temperature, accelerator pedal angle, oxygen content in the burnt exhaust gases as well as many more parameters. Using the information from these sensors it can then add the right quantity of fuel, at just the right time to provide a good mix of fuel economy, performance and emission control when pulling away, overtaking, pottering down the road or zooming down the motorway.
ECU remapping will not only improve the engines power and torque figures it will also sharpen the throttle response and widen the power-band. This will make the power delivery a lot more linear, which in turn will make the vehicle feel a lot livelier to drive and the engine more flexible. Frequently, the vehicles power output is restricted by the manufacturer for no other reason than to ensure that the vehicle fits into a class to suit fleet buyers. As a driving enthusiast, you do not need or want such restrictions placed upon your vehicles ECU and its performance therefore you can benefit from the hidden power and torque locked away within your engine management system.
The other main benefit of remapping will be a reduction in fuel consumption. With the extra torque especially at the bottom of the rev range you will see a fuel saving as it will require less throttle input to maintain motorway speeds, you can drive in a higher gear at a slower speed as well as helping significantly when fully laden, towing or on gradients and even in start stop traffic.
When we remap a vehicle, especially when fuel saving is the priority we focus on improving the low end torque in particular and widening the power-band as far as we can.
This increase in low end torque will mean less throttle pedal input is required to maintain cruising speeds, when fully laden or when on a gradient. It will also mean that the vehicle will be more comfortable in higher gears at slower speeds as well requiring fewer gear changes overall.
If you combine these factors with adjusting your driving style to make the most of the extra low end torque you will see an improvement in fuel consumption. This is most effective on turbo-diesel engines where the savings could be as much as 20%!