Boosting gives all tanks a bonus to their torque allowing them to climb hills more quickly and maintain a higher speed over uneven terrain. Most tanks will also receive a small boost to their top speed. These bonuses come at the cost of a small reduction in turning ability.
For all hovercraft, boosting gives a bonus to torque as well as a substantial 50% bonus to their top speed, at the cost of greatly reduced turning.
For all aerospace, boosting gives a substantial bonus to acceleration and top speed at the cost of heat build up. Boosting is absolutely necessary for taking off of short runways with large aerospace like the Shiva and Xerxes. Boosting can be used to outrun incoming LRMs, getting out of range of other enemy weapons, retreating to repair more quickly, and accelerating quickly out of a stall after slowing down to take a shot.
Note: Holding [Left Shift]] does not cause VTOLs to boost, but instead vectors their thrust horizontally.