To move the vehicle smoothly and to save on fuel, push the accelerator down gradually and wait for the vehicle to build up speed.
In vehicles with automatic transmissions, the gears will change automatically for you. With manual transmissions, you have to release the accelerator and re-apply accelerator pressure as part of your gear shift.
To drive with precision, you must vary the accelerator position smoothly by small amounts. Accelerating too quickly can lead to a loss of control of the vehicle, especially on gravel, snow or ice.