Its 2000. I will post other questions from the owners manual.

I have historically never been good at "doing what your told" without some reasoning behind it. Knowing why things are the way they are. Helps me evaluate new products and processes as they are made available. One of the reasons I ask is its safe to assume the process of producing blended fuels have changed in the last 12 yrs.

I dont see much on the part 2 of the question. Which is if the motor is designed to work with 87 to 91 oct. Is there any advantage to using the higher octane?