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 2006. Every subsequent series that has the レンジャー 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 (竜龙)