If you only drove 2k miles a year would you still change it every 6 months? Doesn't that also mean you should check the date on the oil when you buy it? What if its been sitting on the shelf for like 6 months?
Also, on the Honda item I'd be shocked if it uses RPM's - I'd bet it uses miles because my indicator drops to 15% at precisely 6k miles each time. I've been sending the oil into Blackstone Labs and have gotten to the point where I run the oil for almost 8,500 miles and it could go further (this is just basic Honda Oil) - so I have to believe that I could run Redline longer than that in a 370Z.
I suppose I could take a sample of the oil from the 370Z and send it in without changing the oil. I've had this car for 2 years now - I changed the oil once with Nissan Ester at 1,100 miles and switched to Redline at 3,100 miles on 3/5/2011 - the car now has 5,900 miles but I haven't changed the Redline oil yet. Seems kinda sad to spend that much on oil and only use like 35% of its life. Guess I'll send it in to Blackstone Labs and ask them how it looks. I'll report back what they tell me.