@Kamesh Krishnamoorthy: Re# 141869-8
Passengers are upgraded to next upper class only. In very rare cases it is seen that it is upgraded to next 2 upper classes. Regarding the loss, instead of running the train with empty upper class berth, IR gives upgradation free so that they can pull in 2 waitlisted tkt holders on to an RAC seat for they get the fare twice. So they are not at full loss.