The "Econ" or "Eco" button, usually located on the dash, adjusts certain things on the car to improve the automobile's fuel economy. Not all cars have an Econ button, but those that do change in similar ways when the button is depressed.
When the Econ button is depressed, the shift schedule, torque filtering and idle speed change to increase fuel economy. Some people claim the car is less responsive and sluggish in this mode and therefore choose not to use it.
Because driver style is a main factor in fuel consumption, using the Econ button changes the way a driver operates the vehicle by taking some of the engine and transmission power away. Some drivers report a five to 10-percent increase in fuel economy while those who use the Eco button on larger vehicles report a saving of one to two miles per gallon. Many car manufacturers are installing these buttons because they are trying to do their part to help the environment and because many drivers have asked for a way to improve fuel economy.
For example, in 2006, Toyota introduced a new feature called "Eco Drive." This feature encouraged drivers to pay attention to their driving and the fuel efficiency of their vehicles. Using this feature which is still included on many Toyota models today, may help to improve fuel mileage by up to four percent while helping the environment.
Whether or not the Econ feature on many cars and trucks is efficient, it does help reduce emissions and may change the way drivers operate their vehicles.