ppastos wrote:I have yet to read any of Q45Techs posts.
(BTW I went with Supertech 75W 140 is that OK for New England winters and summers?)
Then you are missing out on 98% of the verified information in these Forums.
Let me add one other must read, which is a text compendium of Q45tech's posts from the first version of this board and the old Yahoo board. Elwesso posted it with an attached file in Infiniti General.
It will do any recent purchaser much good to read the original post for their rich detailed discussion. Every new member did it up to about 3 years ago, at least the ones who kept their Q45.
75W-90 Synthetic is sufficient N of the Mason-Dixon line, but the wider weight blend won't hurt the differential. I have used Amsoil, M1 and Royal Purple with good results. Change every 30K.