What happened to gasoline in the mid 1970s?

In 1992 my mother in law bought a new Chevy lumina, it was a leftover from a fleet of test vehicles.

It was refered to as a "variable fuel vehicle". It was designed to run on 100% gasoline or 100% methanol (NOT ethanol) or any combination in-between.
It had special parts to run methanol, injectors were bigger, special electronics etc.

I drove that car on gas 100 miles a day for 7 years, I had to fill up every 4 to 5 days. At one point I decided to try E85. I ran the tank down to almost no gas, put in a few gallonsof E85 figuring I could dolute the E85 if it ran bad.

It ran fine! So I tried a full tank of E85, no problems. At one point the price of E85 was much cheaper than gas so I started using E85 exclusively. The most notable thing was I had to fill up every 3 to 4 days. (Was not cheaper in the long run)

From my research, methanol is poisonous to humans with skin contact and much more corosion to metals and some plastics than ethanol or gas. And at the end of the fuel study methanol was ruled out as a commerical fuel.

Chevy supliment FSM, Amazon says "Flex" fuel but the cars was a "Variable" fuel said so right under the trunk lid
Screenshot_20210531-222638.png

Some light reading on methanol as a fuel.

https://www.google.com/url?sa=t&sou...FjADegQIEBAC&usg=AOvVaw0gmONMqA15jS4GYOwCzkX9