My 2010 Toyota Prius keeps running out of oil (about once a month it is completely dry). It is not leaking because I have placed paper under it for several days and there is never oil on the paper.

Mine does the same thing a.d a 2008 Prius! I now change the oil every 3000 miles aand still check it weekly...... it still goes low and i have add a little! It's a common problem so don't freak out like we did. Still a great car and we have 225,000!!!

As the vehicle gets older the 0-20 oil does not work, thus get the high mileage oil and it will last much longer as its slightly thicker.

My mechanic said there are two know causes. One the piston rings get sludge built up and don't seal properly or you have a defective PCV Valve. They both cause the car to use oil. I had this happen on both of my Priuses after about 130,000 miles.

My 2011 Prius has just started losing oil. Almost dry before I discovered. Got a yellow caution light that tipped me off. It would come on very briefly and keep, usually when cornering. No evidence of oil leak in garage or parking spots. Hoping there are no major issues and can just monitor oil level and keep driving.