I’ve given long rides to people where I felt generous and just let everyone off the hook,not paying the gas money, often at huge expense to myself.  But I’ve noticed a pattern perhaps it was a reluctance to ask for the money as if that’d be rude.  And that’s really stupid.  Because in all fairness it’s my money!  So now, I just ask for it.  And I’ve found that there really isn’t any difference in people’s reactions.