Yes there are 2 types. You need to find the one for wet clutches (if you decide to use it). I'm sure the gearsaver oil is very close to Hypoid. Kevin said anything from 75 to 90 is fine. And hypoid oil is rated differently than regular oil so the 75/80/90 wt. does not compare. So the thinness of the oil is not a good indicator. As far as hypoid oil goes, it is made for heavly duty gear protection. That's where Kevin got his information. He went to a helicopter mechanic and asked what "super lube" was used in helicopter transmissions(mega heavy duty). Mobil Hypoid the wrench said. The oil molicules are modified to withstand breakdown in "sheer" (as in gearboxes). What I am going to befor ethe next race. He was a head wrench for Kaw racing the H1 and H2r's. They had a lot of tranny problems before the switch. Thats good enough for me. But Zooke is the Suki expert, so take what I say as information.