What is fuel that will ruin orings?

Fuels that contain high levels of aromatics, such as gasoline, can degrade O-rings, particularly those made of rubber materials like nitrile or neoprene. Additionally, fuels with high ethanol content, such as E85, can also cause swelling or deterioration of O-rings. It is essential to use fuels that are compatible with the specific O-ring materials to prevent damage. Always refer to manufacturer guidelines for the appropriate fuel types.