.Hi finally registered. Been learning a lot from the forums. Now need help on deciding what oil to use. .its 2007 350z. With 53000 miles on it. Just bought it with 48000 miles and right after switched it too royal purple since that what I had in garage. Its a daily driver. 50 miles a day four days a week. I do get on WOT maybe twice a week. I work in a castrol quick lube so I have access to all there oils at a great discount. But we also carry redline gear oils so I can basically order anything from them also at a great discount. (Five dollars to do my tranny). So I've been thinking about either GC castrol which on these forums is good stuff I hear or redline 0w30 which is ester based n nissan recommends ester oil I guess