Back in 2004, several automakers got together to create a more pure form of gasoline to meet strict standards set by the U.S. Environmental Protection Agency (EPA), now known as Top Tier gasoline.

My 1965 Mustang has been sitting in a field since 1984 and I am worried about varnish buildup in the tank before I fire the engine. I drained the fuel and it smells OK, but I am worried about varnish ...