Hey guys, new person to the forums here. I'm a pretty big car nut, but am only versatile in Audi/VWs. What kind of oil is best for my 2001 Honda Civic LX commuter? It has 128k miles on it, driven 100 miles a day, 90 of them highway, usually around 75-80mph, with the occassional traffic. I don't drive crazy or super fast with this commuter car. I live in Southern California, so the weather isn't too extreme. Before I started doing the maintenance on the car, the dealer did all the maintenance, so I'm assuming they used 5w-30 conventional. The first oil change i did on it was M1 5-30 with a Fram filter, which I left in car for about 7500 miles before the next oil change, which Autozone ran out of M1 synthetic so I used Castrol GTX conventinal. Currently coming up on 3k oil change, and would like to know what is the best oil for my use. I know AutoZone has Castrol Syntec or Edge on sale currently with a Fram filter, should i go with that, or another brand? I am looking to extend my OCI and also prolong the life of this engine. Thanks