I have a 2005 Prius with 155,000 miles on it. I replaced the PCV valve at 120,000, but my car is still using a quart of oil every 1000 miles. I see no smoke coming out of the back when I start it up in the morning. Is this excessive oil consumption normal for a car with this high mileage? Can I get away with using an oil of a higher weight or a synthetic that someone could recommend? Thanks!
