something I just remembered also is that when Tractor Supply here in my area was selling the Opti2 that was being packaged under the Arnold brand name, it also was a 1.8oz package that was said to be for one gal of gas mix., it was called Arnold 1 Premium Mix if I remember right.
Sears also sells prepackaged Opti2 under the Brand ( Sten Mix ) it is also stated to be 1.8oz for 1 gal of gas which is 72:1 mix.
Lowes sells the Arnold 1
Who knows maybe Interlube thinks that most people wont really milk the package for all the oil it has in it and the extra is to make sure that even if they just turn package up ad pour they will at least get enough oil in the mix to be at the 80:1 - 100:1 ratio, kinda a way to make the mixing from the package more idiot proof......LOL! just a thought.