#4! The others don't even compare.
I got on a BMW aout 9 years ago and sold all the other brands I owned and I haven't looked back. If you ride one, I bet you'll do the same.
I've ran 87 every fill up in mine since it was new. It's a 2003 FLSTC. No problems in 45,000 miles.
I used 85 octane a couple times when I was down in the southen states on trips. It ran fine too.
2004 Honda Pilot
Mobil 5W-20 Full Synthetic
Napa Gold Oil Filter
93,629 miles
Old fill (That I just drained):
Quaker State 5W-20 Full Synthetic
Napa Gold Oil Filter
7,239 miles on last fill