Originally Posted by
alphaod
I drove two cars from SFO via PCH and Route 66 to JFK; they never batted an eye. I paid a lot for these rentals, so I don't expect them to really care.
You can't compare a one-way rental to one returning to the same location. For SFO-JFK they know you're going to do at least 3k miles, and charge you for it. For NY-NY they expect you to do a few hundred.
That said, I agree with the other comments to just do it. It says unlimited miles after all...