Pics I’ve seen, freshly serviced tanks had tracks with little or no sag. My deduction is that the material used in PzIV tracks, bushings or pins wore pretty quickly, and needed frequent tension adjustment. Your option to portray them tight or not.
I would imagine that the amount of lieage that tanks in WW2 went through would mean regular track tightening and changeing. Our Warrior tracks were meant to last 5,000km before changeing, but they very really lasted that long.
Kenny- Speaking of devil, I have been working on aftermarket track for my very old Tamiya kit. Just like yours, the rubber bands that came with Tamiya was in poor shape so I had to buy one. I got this for $35 from RZM. Stay away from Hobby Depot as my order never went thru for weeks…
Pz IV tracks, like all German vehicle tracks, were “dead” meaning they weren’t under constant tension when at rest. Depending on the position of the idler, the wear on the tracks, etc. the sag can vary and you will see on photos if you look at enough of them that some sag is almost always present…but not usually the heavy/wavy sag that modelers tend to go with for aesthetic reasons. The suspension design on the Pz IV with the number of return rollers for the upper run means that there wasn’t a lot of “slack” space for sag to present to begin with, so you should bear that in mind as well in your decision. I would definitly recommend not using rubber band tracks for many reasons, sag being one of them but not the only one. [;)]