Self-evacuating oil drains use shop air to empty used oil and get the equipment back to the service floor. Capacities include 18, 25, and 27 gallons. An 18-gallon oil drain works well for shops that don’t do a ton of oil changes and have fewer bays; whereas, shops that have an oil change focus with multiple bays would need drains that hold 25 or 27 gallons of oil.
With self-evacuating oil drains, no auxiliary equipment—such as a diaphragm pump—is needed. So, the initial investment of a self-evacuating oil drain is lower because you don’t have to add the expense of a diaphragm pump.