Flutter Nutter and Daddy's Buddy!

Driving past the car dealership near home, I hear...  (I am referring to Boys because I can't remember exactly which one said what. )
Boys:  That camo truck has gas in it.
Mom:  I am sure it does. (Afterall, how could one drive without gas in a vehicle?)
Boys:  Gas like Grandpa has. 
Mom:   Trying to not laugh.  Which Grandpa?
Boys:   The Grandpa with gas. 
Mom:  Trying so hard to not laugh.  At this point I am thinking they are refering to the gas tank we take out to the lake to fill the boat and ask if that is the case?
Boys:   Noooo,
Boys:   But that Grandpa. 
Mom:  Ahhh, Grandpa D.  Are you refering to his Oxygen tank? 
Boys:  Yes, and Oxygen is a gas.
Mom:  Right you are!  More chuckling quietly to myself.  So glad we had a bit of clarity there.