The VQ35 engines tend to show "SOME" wear metals for approximately 10k miles. If you switch to synthetic early, this will obviously prolong this. This will be the first car I've owned since 1994 that I haven't switched out to synthetic at the first oil change interval. I'm torn on this. I get free oil changes from my Infiniti dealership for the life of the car. I'm torn because free is free, but I'm also concerned for the environment. I've used Amsoil since 1994 and I've always used extended drain intervals. Change intervals based on Blackstone labs analysis. With my 2k2 Maxima I did 10k intervals even though Blackstone showed very good numbers. Most VQ35's can go between 10k - 15k change intervals with Amsoil. This is according to the spreadsheet posted on maxima.org. I had a 2001 Durango that I changed once a year. A Honda Civic that I changed every 20k. Nissan Titan that I changed once a year. I now have a Nissan Quest which I will start on 10k oil changes. I certainly wouldn't change my oil before 3750 miles. It's a complete waste of money and the impact on the environment.