Read up on octane and elevation...detonation is a bigger problem at low elevations. Most cars that require 87 only require it at maybe 2000' or less. Those of us at higher elevations can run 85 with no detonation. The thinner air compensates for the octane.

“In a time of deceit telling the truth is a revolutionary act.”
― George Orwell

It's not over when you lose. It's over when you quit.