I have always changed my oil every 3k miles and I figured synthetic would be a waste every 3k so I have decided after searching the forums on Castrol GTX 5w30 for my everyday driving and occasional heavy foot days... but should I use a Nissan filter or would a Fram do just fine?

 

Excellent choice on the oil....I've been using Castrol for 20 years and have never experienced any kind of oil related issue. I use the Fram Extra Guard or Tough Guard depending on what's available at my auto store. Also go with the 7317 instead of the 6607.....the filter is the same thread and diameter but a little longer(1/2 inch or so) so you get just a little more filter capacity.