the fact of the matter is that toei and bandai have been using gorenger to exclusively refer to the first super sentai series since at least every subsequent series that has the ending has been ranger you can see this sort of thing on any of the print material released by them lately has it as gorenger while all the others have been turboranger zyuranger dairanger kakuranger ohranger carranger megaranger timeranger gaoranger abaranger dekaranger magiranger and gekiranger i believe gorenger is also plastered across their vehicles ryulong