I have had a couple of extruder jams recently when doing the first layer infill. I do that at 195°C to avoid it sticking to the raft. It seemed that ABS was much harder to extrude at that temperature, so I did a range of tests to find out how flow rate and force vary with temperature.
I used my lead kebab test rig with this extruder, which has a 0.5mm nozzle: -
Most measurements are averaged over 8 tests of extruding 40mm of filament, so it took a long time to get these results.
These are the basic measurements: -
Flow rate for a given force seems to increase fairly linearly with temperature. The single points are the weight that I found gave about my normal extrusion rate of π mm3/s. Below are the same points plotted against weight: -
So force does increase rapidly below 220°C.