What are the effects of ECU remapping?

Many people say that ECU remapping doesn’t affect fuel usage; however this is not technically true. Because of the process involved in ECU remapping more fuel is going to be consumed in order to produce the increase in power. If the car is driven in an enthusiastic way after the remap has been carried out then the fuel economy will not increase (and in some cases may decreases). If, however, the driver modifies their driving style to make the most of the increased power and torque throughout the rev range then fuel economy can be increased. A good example of this could be that the improvement in torque produced by the engine after remapping means the driver no longer has to drop down a gear to maintain speed on an incline or may not have to change gear as frequently in traffic. All of these little things add up to an improvement in fuel economy.