Regular aviation gasoline (avgas) is 100 octane low-lead (100 LL). It's probably to only leaded gas made in America today.

Many older planes were built to use 80/87 octane but that was phased out of production in the mid 1970s (avgas is a tiny fraction of US gasoline comsumption). Many of those planes have a supplemental type certificate to use high test auto fuel but ethanol causes problems. I ran auto fuel in the Cessna for years but we had to replace the fuel sump drains regularly because ethanol ate up the seals and caused fuel leaks. I tried running it in my Cherokee but quit after losing a lot of fuel to leaks. Since I upgraded the engine's compression ratio to get more horsepower, I have to run 100 LL. The FAA has tested a 92 octane no-lead fuel but as far as I know, no one is selling it yet. I don't know if I'll be able to use it in my plane without modification or not.