As seen at S-Oil, across from Homeplus in Ansan.
[Top section of photo]
Gu Do-Il is riding.
Giddyup ~ Giddyup~
Gu Do-Il is riding and
he's full of energy and doesn't get tired!
[Bottom section of photo]
Good – "Gu D", Oil – "o-Il" = Gu Do-Il [Get it? "Good Oil"]
I am Good Oil.