first off i'll state i did NOT have a hulgar for this test;
went from 400-500 with out consuming any potions, (dont know what my towers Item find/quality was but had a 99 Black widow)
only counting Yellow potions after converting all the blue/whites i had the out come was this:
After Transforming all of the Speeds / Water my final outcome of Strength and Crit were 43 str / 49 crit
Looking at the water/speed you can see i would be able to combine all of them and make 54 more potions, but i kept making more speed / water giving me only a total of 25 more potions that i actually wanted.
Either Transmuting 2 of same potion should not be able to outpute the Same potion, or the odds of Life/speed should be reduced after a certain level i think, Especially Lifes considering their beyond useless at bonus level time, and at bonus your carry will (unless hitman) be at .1 or even .0 leaving speeds useless as well.