Just an observation about the V6 in the R51 Pathfinder.. It seems that many have had to have there timing chain and guides replaced on 05-2009 models but what is interesting is that there are many people who have not needed to replace there timing chain and guides even with high millage. Case in point I have a friend that has a 2009 Pathfinder and he has 156,000 miles on his with the original chain and guides and it is the quietest V6 R51 Pathy I have ever listened to. He really does not care much about what oil he runs either he goes to Jiffy Lube between 6,500-8,000 miles and buys there lowest cost oil change. There are also several on this forum as well as ClubFrontier forum with the original chain and guides with high millage. Just seems to be the luck of the draw.
Just a side note the timing chain and guide issue was supposed to be fixed on 2010 on up VQ40DE 4.0 V6 Nissan motors.