Pre-oiler???

You shut the valve when your motor is running, then shut the car off. Before you start it, you open the valve and it pre oils your enigne before you start it.

It works sorta like a pressure tank on a water well.

Considering that I have been tearing down engines for almost 25 years and have found that if you change the oil religiously and take care of your car the engine will last for a very long time. In 1978 my dad and I pulled the 429PI from his T-Bird because it had too much compression and would not run on pump gas anymore. A friend wanted it for his jet boat. We disassembled it and everything checked out within factory specs even after 300K miles.....2-3K of that every summer pulling a big camping trailer. The guy used the engine as is....it is still on the factory bore and bearings 25 years later.

Take care of your vehicle with regular maintenance and you really do not need those expensive pre-oilers. Make sure you use an oil filter with an anti-drain back valve.

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.