Never flown an MD80, so wouldn't know, specifically.
What I mean is that if your profiles are like airnets, which are from what I've heard a "fly it like you stole it" profile, as opposed to slowing to 130kts 25NM out you could fly at more efficient speeds more often, or make approaches which were more steep and make up for the lower fuel economy that way. I distinctly remember being stuck behind an airplanes from PenAir and Era, turbo props like ours, with similar capabilities flying the last 30NM at Vref, even in Vmc. What the flight manual will allow, I don't know, however, you could certainly shave off precious minutes here and there to save on fuel by having profiles which were designed to maximize efficiency, and reduce flight times.