What happened to gasoline in the mid 1970s?

[QUOTAE="Norbert Schmidt, post: 1973462445, member: 58087"]Hi,

I wasn't around in the mid 1970s. I've been reading old threads here that containing "octane" and reading articles on the web. What I've gathered is the following which may be mostly wrong. I'd love to know what the real story is.

Before the mid 1970s, people used leaded gasoline that had approximately 88 octane. The lead acted as an anti knocking agent and compression ratios could be as high as 10.5 like in a Chrysl


A stock 340 10.5/1 motor never ran on 88 octane. ps Sunoco 260 was were it was at!