Many Lowriders feature custom hydraulic suspensions that allow the driver to alter the ride height at will. At first, aircraft pumps, valves, and hoses were used. Later it was found that the liftgate trucks had more compact units and these units were soon replacing the aircraft units. These systems range from simple to complex and are usually measured by the number of hydraulic pumps (generally 2 to 4) used to control the various hydraulic combinations that ultimately produce a specific motion from the vehicle. These pumps are powered by multiple batteries installed in a rack in the trunk of the vehicle. The speed at which the car lifts depends partly on the voltage generated by these batteries, which can range from 12 VDC all the way up to 120 VDC. The most common motions are dipping/raising the four corners of the vehicle, dipping/raising the front or rear of the vehicle (front, back), dipping/raising the sides of the vehicles (side to side, which started around 1978), and lowering/raising the vehicle as a whole (pancake). A skilled switch operator can manipulate their controls to raise one wheel completely off the ground (3-wheel motion), or to hop one end of the car completely off the ground. Around the mid-1970s, it was found that adding more batteries could get the front wheels to actually hop off the ground. This created a whole new sport with respect to hydraulics in Lowriders. Cars at that time could lift the front wheels off the ground about the height of a 12 ounce can.[clarification needed]
