[SampleMan]

Putting diesel in a gasoline engine could damage lots of seals, hoses, and o-rings. What is the mechanism for that? Diesel is not corrosive and it has greater viscosity.

[editor-surveyor]

Diesel has many components, most of which are deleterious to the cohesion of the seal materials used with gasoline.

Its much the same problem as using petroleum based solvents to clean brake parts. Its not a corrosion issue.