I read this thread ...
http://www.vehicross.info/forums/showthread.php?t=3756

The 3.2l engine is reliable but the 3.5l seems not so..
If i just need to put and check oil regulary i don't mind but i dont like the fact that many 3.5l engines failed with very expensive costs for repairs..I already check oil for my Frontera after offroad trips..