comeback to the comeback

my friend needed some stuff from the grocery...

me:  'i need to gas up...  let's bring my car...'

friend:  'no...  let's bring mine...'

what followed was a series of 'my car - no, mine' exchange...

i delivered what i thought would be a decisive statement:  'how am i gonna gas up if we bring yours?!'

well, it wasn't logical enough...  i was knocked down with, 'you gas up later...  let's bring mine now...'

: }