which brand of motor oil do you guys think is the best among the general brands? Is Quaker State a good brand?

 

Mobile one syntehtic is the one i use.

If you don't want synthetic, I would prefer Catrol gtx

 

They are all basically the same, if you are comparing non synthetics. If you use non synthetics, oil changes every 4-5k miles is fine for your engine. Any more won't harm your engine, but it will be mainly for peace of mind. When shopping for non synthetic oil, shop mainly by price. What kind of oil do you think the Nissan dealer uses? It's not "Nissan Oil." It's whatever 5w30 and 10w30 they can get the cheapest. It might be Valvoline, Pennzoil, etc...doesn't really matter.

If you are using synthetics, the only way you will make that cost effective is if you extend the oil change interval. Something like 7500 miles is a good synthetic change interval. Unless you live in super freezing areas (like where it gets below 0), synthetics won't make much of a difference. But man, they will save your engine during startup if it gets really really cold. Most people here like Mobil 1 Synthetic.