I was very sure that TIEing from 2 or 3 enthusiasm would bring me back to 5 (that's what happend every single time in the examples I've read on our french forum). And that was just another example of my "bad luck" in the end of season,
TIE will raise your enthusiasm with about 30-35%. Let's say you started with 3.0 and TIE is 33% extra enthusiasm, 3.0 + 1.0 = 4.0, just simple math