no, the outcome is not the same...
take for example a whiskey and ginger, my drink of choice, equal parts whiskey and diet ginger ale = 20% alcohol once mixed = fucked up. the same goes for a whiskey and cola... to get the same drunk off JWeed (5% alc) as one glass of whiskey ginger you would have to drink 2 of those god awful giant cans packed full of sugar. sugar = hangover/vomit = no thanks...
basically what i'm saying here is that nobody mixes their whiskey and cola in a 1 to 4 ratio unless they're a huge pussy. besides, buying a handle of evan williams and a 3L bottle of cola will cost about 1/10th of what an equivalent amount of JWeed would cost.