The right oil
 

So I've had my Z for about 9 months now and just got my first oil change. (weekend car) It was freshly serviced when I got it. The oil always ran at minimum 220 but after reading everything I figured it was normal and just needed to get myself a cooler.

So after going to Nissan and getting a service and paying the extra for the ester oil (which I had to ask for) it now sits around 190-200 for normal driving. That's a 20-30 degree difference!

I'm guessing the Subaru dealership I found it at probably put the wrong oil weight in or something. Glad I didn't push it too much with the wrong oil in it.

I'm not sure this needed a new thread (there are threads on every possible oil topic already). But are you sure that weather or driving style or some other variable was not partly responsible for the difference? Different viscosities will indeed vary oil temps, and even different oils of the same weight will vary to some degree. But 20-30 degrees is like what you should see when you install an oil cooler. I would be very surprised to see that much difference by just changing oils.

I believe it's called winter.

With that said, Riverside can get awfully toasty in the summer. With traffic and spirited driving you may want to look into an oil cooler.

Herein Florida when it gets into the 30's every blue moon my z sits Round 190-200 with normal driving

Well winter is what would be the obvious conclusion but even on a cold night, normal street driving would still have me at 220. Only if i was flying on the freeway in the cold would it lower.

Assuming the outside temp and driving condition is the same, it is unusual to have such a huge difference in oil temp even with different oil.

Since you only have the car for 9 mos, socal weather has been nice and warm til the last few weeks where the temp was unusually cold. So my guess is that it is outside temp related or if not, then there may be something wrong with the car.

my car has been around 210-220, but during the cold days around xmas, it was around 190-200.