Red is gas, Yellow is Diesel!

[Industrial Toys]

I bet the seals were more an issue of poor quality rather than diesel vs gasoline.

 

[Jstpssng]

Considering that he has a new tractor and years left on the warranty I don't blame him for not taking chances to save $25.
I knew a kid once who added what he thought was 10-40 to the company truck he was using. It turned out to be Roundup in a repurposed gallon oil jug, and took every seal out of the newly rebuilt 305 engine.