Is this your lucky day or what? The forum that you joined a mere 4 hours ago, has a sub-forum labeled Updated Official MODS thread, and included are 9 pages containing 170 posts about mods to cars just like yours. Enjoy deciding what to spend your money on, and how to do it.

*UPDATED* Official Altima MODS Thread
THANKS QR FOR PROVIDING THE ORIGINAL POST TO HELP THE NISSAN ALTIMA COMMUNITY. GAS INFO It is recommended to use premium in the 3.5L (if you want it to operate correctly) , the 2.5 does not need premium. Please do not make any more threads regarding gas ratings. Read this article for more info...