I don't know about a ton more, but it was a noticable amount. I remember my first firing trip was on 487. I did OK and thought "well, this isn't as bad as I thought". The next trip I got 488. I thought it was going to suck me in the door. Everytime I gave her a fire she seemed to say "Thanks! I'll take this one and you get me another..and another..and another."
She steamed OK, but man she could eat coal. I remember the hair burning off my left leg from standing next to that open firedoor most of the trip.