I would question the statement above:
"Diesels are notorious for having nearly the same performance, loaded or not."Go to:
http://forum.dieselrvclub.org/index.php/topic,6594.0.htmlDownload/view on-line Caterpillar's "Understanding Coach/RV Performance".
On pages 6 and 7 are the performance numbers/HP requirements for different weight vehicles. You will find that on flat ground, HP demand is much more related to aerodynamic drag. But on grades, weight becomes the overwhelming factor. While the View's Gross Combined Weight is less than the coach examples, the same physics principles apply.