[Kelbyat07]

Originally Posted by swarb

You really don't know unless you send your oil out for testing. You can look at other people's test results with a similar setup, but in the end everyone drives different and in different environments/fuel/car/oil/etc.

2013-2014 factory recommend interval is 7,500miles.
2015(brz at least) is 6,000miles
Suggested/recommend cut in half when running e85.
But look at the test results, some people have good test results and some can run up to 10k on a stock setup.
Do whatever you are comfortable with, get it tested and go from there. I would suggest 4k(your 3,500 ok too) and get it tested, good medium between 3k and 5k, while be a little bit on the safe side.

Alright thanks. I think all I have to worry about right now is which brand of oil to use haha