Ford is offering free upgrades to United States and Canadian hybrid customers to improve their fuel economy.
The company plans to recalibrate the vehicle control systems on 77,000 Ford C-Max and Fusion hybrids and Lincoln MKZ hybrids from the current model year.
Some customers have complained that the cars aren't getting the 20km per litre fuel economy promised in Ford's advertising.
Ford will increase the maximum speed the cars can be driven in electric mode from 100km/h to 137km/h).
It also plans to make better use of the grille shutters, which improve aerodynamics; reduce the electric fan speed; shorten the engine warm-up time and minimise use of the air-conditioning compressor.
