I'm running 87 in mine and it is running fine. No knocks or pings. If your happy with the price and what not of the 89, stay with it. You could try the 87, but if you do get any pings or knocks go back to the 89.MAN! I have had my 07 Radiant Red Tundra for a week now, and 540 miles later I'm glad this is the truck I bought.
I came from a 2001 F-150 Supercrew. I loved that truck! But the Tundra far exceeds anything on the Ford.
Still not used to those HUGE mirrors! I'm afraid I'm gonna take out a few mailboxes before I do. Maybe even a bicycler or two
Got a question though on octane level. I am using 89. Was wondering what most of you would suggest.