The RV industry is so price sensitive (or paranoid, if you prefer), that Workhorse chassis went out of bsuiness when they could no longer offer the GM 8.1L gas engine. Even though they had a nicely priced diesel from their parent company, Navistar. Buyers at the entry end of the motorhome market are buying slide-outs, big tvs, and other living features, not diesel engines. An extra $12,000 will buy a lot of amenities.
Strictly on a engine performance basis, a front diesel is head and shoulders above a gas powered unit, but engine performance is only one ticky mark on the buyers wish list. And probably not on Momma's list at all.
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL