To better understand low gearing, low rpm's, low speeds we have to look at how trucks were used when they were designed and built. Look at applications WORK, hauling, pulling farm wagons), not the highway speeds and applaciations of today (transportation between 2 points with carlike ride and speed).

A horse is a horse but Budwiser's Clydesdales will never will the Kentucky Derby and Secretariate couldn't pull the beer wagon!!!!!