Impulse is a weapon used by player/s in Driver San Francisco, mutiplayer.
Unlocked at lvl (8), the player can 'impulse' a target vechicle of their choice causing (if done correctly) it to lose control.
To use the weapon, player must have a full weapons charge. Once the player has a full charge, they then must shift out and target a vechicle of their choice (using the relicule) and hold down the shift button. Once the meter is full, the impulse will make the target car to lose control. If done incorrectly, the player will lose half of their weapons charge as well as the target car still in control.