I use 87 in my truck. I used premium for a while, but the increase in MPGs did not offset the increase in fuel price. Does anyone have any fact based evidence that indicates long term engine damage, to a 4.7l Toyota endings, from using 87 octane fuel? I believe ever increasing amounts of ethanol can cause certain types of wear, but I don't believe using 87 octane does anything but prevent slightly higher efficiency.
Long term? I've got 16 years and (as of this weekend) 277,000 miles using regular with ethanol. Absolutely zero issues.