deterioration in fuel lines has been busted. It’s really aromatics such as benzene, toluene, and xylene that cause the deterioration in fuel lines and destroy injectors. When lead was eliminated from gasoline, MTBE took its place as a way to increase octane. Then when MTBE was phased out starting in 2004, there remained two cost effective ways to increase the octane in fuel. One was to add ethanol to the fuel, the other was to increase the amounts of aromatics. Ethanol free premium fuel often uses these aromatics to get the higher octane. These aromatics are very strong solvents and ruin early style injectors and deteriorate some types of fuel lines. I’ve provided a link that has some interesting video at the end of the thread:
