Ability to show 4 instead of 3 like the IM608 offers. Makes sense when monitoring bank 1 and bank 2 long term and short term fuel trims, 4 wheel speed sensors, bank one and bank two upstream and downstream O2 sensors. My guess is maybe some of the older platforms processing abilities might not be able handle merging 4 PIDs at once without some choppiness, but I'm sure they could give user the option to only select 3 for smoother graphing display.