Ok so after owning the Spec B for about a year I finally read this whole thread (hey I have to do something at work), anyways I've used Red line 5W30 since I bought the car and have noticed a very tiny amount of oil use if any (and it could all be in my head).
So my environment
Michigan- as warm as 102 in the summer, cold as -12 in the winter
Test and Tune 4-5x's a year, might autocross next year.
10,000 miles a year mostly freeway
Change the oil ever 3 months even if were not at 3000 miles, OEM blue filters
I like the Red Line but have heard people like Infamous us the Rotella T-6 5W-40 are there any drawbacks to switching from Red Line? Form reading it seems most people love the Rotella.