Although due to its size, 747F are usually used at a higher percentage of the time. The large freighters (7437, 777) are mostly used between hubs and for long-d

Although due to its size, 747F are usually used at a higher percentage of the time. The large freighters (7437, 777) are mostly used between hubs and for long-distance routes. That's why having fuel efficient planes (e.g. 747-8) makes sense. What Wendover describes are cargo planes serving hubs, those often only fly 1-2 returns a day, so having a very cheap plane with higher consumption is worth it (e.g. A300).