Hi guys. Just bought an '04 Prius. Toyota in North America says 5w30 with 5k oc, everywhere else they recommend 0w20 synthetic. I'm looking for maximum engine life with good fuel mileage. Instead of using questionable 0w20 for fuel mileage I was thinking of 5w30 high quality synthetic with a 7k oc with filter for maximum engine life, and for extra fuel efficiency I was going to add half a bottle of MoS2–Anti-Friction which they claim is also good for engine life. One other thing I was thinking about adding a half a quart of synthetic lucas oil stabilizer. This is because the Prius engine is always cutting out and starting because it's a hybrid. I thought the Lucas would help the oil cling to the metal during engine stops. What do you guys think? Thanks in advance. Yay, my first post here!