The 21120 Lube Skid is Sage's largest skid-mounted oil-changing system, with four 60-gallon new-product tanks and one 120-gallon used-product tank. Oil Vac Lube systems work on a patented vacuum and pressure process. An air compressor creates a vacuum in the tanks for vacuuming used fluids from components, and pressurizes tanks to blow fresh fluids into machine components. Sage claims maintenance times can be cut as much as 50 percent using an Oil Vac Lube Skid rather than gravity drain. Estimated list price: $14,280.