Originally Posted by bamabikeguy
I've use the lowest, 87 octane for a long time now, in fact, it was advised I quit burning 91, because the lower octanes were the manufacturers rec...(something technical about the explosion temperature).
I have to use premium because I have a turbocharged car. The higher octane helps to prevent preignition due to higher cylinder pressure. And yes, 87 is more efficient in a normal low compression engine.