I guess I should have added, the only vehicles I've seen with a pre-oiler are drag only vehicles. I'm not totally sure that they're needed, but seem to be great insurance. Now on a turbo'd motor, I think that the post shutdown oil circulator for the turbos is a great idea, you can really cook a turbo without one of these, although I haven't seen any in a drag only vehicle, but these guys have the turbos gone thru or replace them for the latest innovation quite regularly.