I have a Spinner II on my big rig and it works very well. Only problems I have had with it is the schrader valve on the air supply had to be replaced twice in 1. 7 million miles. If your Spinner II is like mine, you will need a compressed air supply plumbed to it in order for it to work properly. The air pressure makes for a forced gravity feed sending the oil back into the pan after its run through the spinner. Without it, the oil level gets up to the bottom of the rotating portion of the unit, creating drag and stopping the unit from working at all. When functioning properly, the centrifuge itself totates at nearly half the speed of a turbocharger impeller -- about 60,000 rpms --- enough to create a force of 6,000 g's on the oil, spinning out contaminants small enough to go through any other kind of filter. Even soot particles are collected in the centrifuge.