When I bought mine in March this year, I had this very question and I believe it had recommended the 87 oct. as I recall my dealer saying so. SO...that's what I use. You've probably discovered this by now though. :D
I also just discovered this board after husband decided to change the oil this time and couldn't find the filter. He's done this hundreds of times, just not on a Lexus. Thanks to someone else having this very problem, he found it. It was tough for him to swallow his pride and ask for help on this one I assure you!
THANKS!
