I can live with a zero grace period too, if my flight schedule dictates that I don't need it (e.g., a 5pm arrival and then a 3pm departure the next day pretty much guarantees that I won't need the grace period). But there are enough times when I do want/need that extra 30-60 minutes, in which case Hertz becomes more expensive, by a factor of roughly 33% (extra hour charge). Particularly when renting for a day/weekend in Manhattan.