Blood is mostly made up of water, as are our organs and muscles. To read specifically about edema, swelling caused by fluid retention where excess fluid is trapped in the body's tissues, see our article Edema: Causes, Symptoms and Treatments.
If you use the Amsoil Ea15K01 and the ASM oil (For 3rd gen Prius), then you can safely go 15,000 miles between oil changes. I drive 25,000 miles per year in my Prius. Amsoil backs up their products by a written warranty.
Revised by BoatUS editors in April 2012. Engine manufacturers typically recommend an oil change every 100 hours, and at least once a year. Even if your engine manual allows for a longer interval between oil changes, changing the oil more often will extend the life of the engine.