Good Evening, I am assuming the Formula + is a gear lube, not a motor oil. It's for the Primary and Transmission. Harley doesn't state the specs, which is really poor if you ask me. Does anyone know what the specs are? Is it a 75w/90 gear oil? Secondly, Baker Transmissions recommends Spectro 75w/140 for the HD transmission, would there be any difference in using Mobil 1, or Valvoline or Amsoil in the same spec? Is there something special about Spectro? Thanks.