Year=1991 Make=Nissan Model=Sentra SE-R Motor=SR20DE=2.0L Current Mileage=201,658 First a little bit of history and current status on the car. The previous (2nd) owner put over 150,000 miles on it himself. He also took care of the religiously, handed me a folder about 3 inches thick with all his receipts and work done to the car by Professional shops, i.e. Nissan, Firestone, etc.. The car runs very strong for the amount of miles on it, partly attributed to the maticulous maintenance performed on it. The clutch is slipping but I hope to be replacing it in the next month or so. I've done a complete tune up on it; Platinum Plugs (OEM), Wires, Rotor/Cap (OEM), Fuel Filter (OEM), Air Filter (OEM), Oil Filter (OEM) and last but not least Exxon Superflo 5w30 (weight recommended by Nissan for this motor). This is the only car I have. Weekdays it will travel short distances, I'd say about 5-7 miles each way as I take the train to work everyday. It will also by my car for the weekends, my GF lives about 20 miles away, so I'd say on the weekend on ocassion I'd put about 100-150 miles. So average about 200 miles a week, maybe more. Here's where I need the help. For now I've put in the superflo because its the only oil I had lying around. What I want to do is use a qood quality, yet, inexpensive Dino oil to make this motor last me at least another 50,000 miles. We, as in my brothers and I, are big fans of Mobil Oil. Is that considered a good oil? There is so much information on this boards it sort of over-whelming for a new person. I've read Mobil is okay, but this is better, or that is better, etc.. Also should I change the oil every 3K or 5K (this is what I was thinking)? At some point I was thinking about adding some of the additives mentioned on this board (Auto RX,etc), but I've decided to hold back on that since the car runs excellent mechanically. Its not someting I've totally stop thinking about, just something I don't want to use right now. Any advice on this too? To make a long story short: 1) What is a good oil I can use? 2) The OEM filter has a plug in the back. Is this good enough or should I go with a filter that has better elements? 3) What interval should I change the oil given my driving habits listed above? 4) Should I use any additives, just yet? Sorry for the long post. Thought i would reach out to some of the people on this board for help. I would appreciate any help. Thanks much.