Is there any benefit to using synthetic oil in a new Prius? If so, when should you change from conventional oil to synthetic?
Much much discussed. A quick search for "Synthetic Oil" gave dozens of hits: Synthetic Oil Search Hit List I think a search for the term 'Mobil 1' would also give a lot of hits and info. Many of us use synthetic for a variety of reasons, but mineral oil is more than adequate for the job and saves some money.
Here's my opinion: 1. probably a slight but unmeasurable increase in MPG. probably a more than slight, but still unmeasurable, increase in the life of your engine. I would say do it if you live in a northern (or superhot) climate and/or if you change oil yourself (it is very easy, and the additional cost is then only about $15 per oil change, and you can feel more comfortable with Toyota's recommended 5k intervals). I did it (Mobil 1). 2. Do it at your first regular change interval: 5000 miles. If it's bugging you, do it at 3,000. Don't waste the dino oil by doing it at 600 or 1000. Enjoy your car! rpm
