[runeridr]

Has anyone read about the engineering that when into the engine cycling? I have always been told that the worst thing you can do to an internal combustion engine is to start it since there is no oil pressure to lubricate the parts. The Prius does this so many more times per drive than any other car. When the engine shuts off there is no low oil pressure light, would the light come on if there was a problem with the engine running? Does the engine have a conventional oil pump or an electric one?

 

[RSnyder]

Be sure to check out John's Prius site:
http://john1701a.com/

Open the Prius Info list on the left side and click on Misconceptions. Scroll down to: Restarting the Engine frequently is harmful?

To answer your specific questions: The trochoid gear type oil pump is driven directly by the crankshaft. So it is not pumping while the engine is off. There is always oil left over on the cylinder walls from the previous run. Since fuel is not injected until the engine is up to speed and oil is up to pressure, it doesn't get washed off the cylinder walls as it would in conventional engines.