Greased Bearings is unlocked at level 2. It increases rotation speed of a Tank's turret and mounted machine gun by 25%, aiding target in acquisition, especially against infantry.
This perk makes the tank considerably more responsive and is a good perk for players who use the tank's machine gun, as it moves relatively slowly and is difficult to use against moving targets. This is advisable on a map or game where there may be multiple targets and target switching is essential, for example two enemy tanks nearby, or an enemy running for cover. It is useful when attempting to engage an enemy on foot that is in close proximity, running around alongside the tank or running past, where without it the enemy player would have more time to escape. This perk also increases the traverse speed of the machine gun mounted on top of the tank if the player enters the machine gun seat while this perk is equipped.