I sent an email inquiry to DPS, and they confirmed currently a motorcycle endorsement is required.
If they plan to challenge it in the Oklahoma legislature, when are they going to act? It's by no means a sure thing and the only have the 2015 session left. Who is listed as their supporters in the house and senate?
At this point in time you would need a motorcycle License in Oklahoma :-( Senator Don Barrington, is the sponsor for SB 255 which will modify Oklahoma Statutes to create an 'autocycle' classification, which will not need a motorcycle license.nor a helmet, even if under 18 years of age, due to the enclosed cabin, car type sears, seat belts and airbags. So I have already written to Sen. Barrington to let him know he needs to "get her done'.