I'm almost to 2500 miles on my 07, and I live in Las Vegas, NV, so I was wondering if it's better to run 5w30 or 10w30? It gets pretty hot during the summer, and stays nice through winter (70s). Also, what's the best synthetic to use? Mobil 1, Castrol, ???

 

Are you only supposed to use 100% synthetic oil ?

 

i've used full synthetic in my other cars, but I don't know what's best for the Z

 

royal purple, mobil 1 are my choice synthetics,

 

read this thread. It has good info for you..

https://my350z.com/forum/engine-and-drivetrain/258663-vq-oil-analysis-and-info.html

 

Amsoil European formula 5w 40

 

Nissan does not specify synthetic or non...frankly it makes no difference for your avg street car, the change intervals are more important

I used 5w30 Castrol GTX, then Valvoline synthetic in my car year round (always with WIX filter), without any incidents before I installed my built motor. 40k + miles, 0 consumption, consistent gas mileage, increased rev limiter over stock

You're not going to really get a concrete answer on this issue, just opinions basically