Wait, so gas
DOESN'T go in the intake?!?!?!
Crap, I better head to the dealer!!!
In all seriousness it says that because it's a retro theme from the '70s challengers. Those challengers had fuel caps that read "fuel". So it's not like some dummy-proof thing the dealer does, haha, just a throwback to the classic, which I personally think is kinda cool.