Well, it is my inference, but there’s a reason that Ben gives Han that ‘oh really’ look, right after the parsecs line. As far as I’m concerned, Han was just using technical lingo to try and fast talk them into paying him his price for the ride.
That was the impression I got as well while watching A New Hope. I thought that Han was just bullshitting Obi-Wan and Luke. Sadly The Force Awakens eliminated that possibility.