This pic is a screen capture (sorry, couldn't figure out how to grab the text), from the ReplayGain values of each 30 second interval of Tom Petty's "I Won't Back Down." The last interval is slightly shorter than 30 seconds.

Note how the Full Moon Fever (1989) version gets louder by about 3.6 dB from beginning to end. The last value (i.e. *06) doesn't really count, because it has a fade out and silence. The Greatest Hits (1993) version doesn't exhibit the same kind of growth in loudness. Also, note how the peaks are different in the FMF version, while they are the same in the GH version.