[EricSorensen]

OK we pay a small fortune for our Ecos and they give us a mile jug top for a gas cap? At least the DEF screws on! This a plastic cork at best. I know there is a thread here on aftermarket caps but there are no threads to screw on and the door doesn't lock.
Eric

 

[sabmgb]

Isn't that a real piece of work. Pay 50K for a truck and get plastic plug that has to be worth, oh nothing.

 

[CJnOC]

I thought that all the trucks gas filler doors lock automatically when the doors are locked? I agree on the crappy fuel cap plug, so I went out and got the aluminum one from Geno's Garage with the built-in magnet so you can stick it on your fuel filler door while gassing up.

 

[zoomie]

I think this kind of filler neck is designed to work without a cap. Lot's of other vehicles are going this way. The cheap plastic cap is just there to protect it during manufacturing and delivery and I believe it was supposed to be removed by the dealer.

Here's an article from 2012 talking about pros and cons.

Pros and Cons of Capless Gas Tanks - Car Pro News