Since some drivers shift gear much earlier than others, gear shifting behavior is a good indicator for eco-driving behaviour. Drivers that shift gear at low velocities and moderate accelerations enter third gear around 30 km/h, whereas others only reach third gear at 45 km/h in the same type of vehicle.
In terms of fuel consumption, the lower the engine speed the better, and the eco-driver advice is to change gear between 2000 and 2500 RPM. The average gear shifting RPM for different drivers however ranges from 1400 to 3000 RPM, depending on the vehicle type and the gear, but mostly on the driver behaviour. This large bandwidth means there is quite some room for improvement by better eco-driving behaviour. The estimated difference in fuel consumption due to different engine speeds can be up to 20-25%.