Advice/Direction towards 30'(+/-) Diesel Class C

In that size range, new diesel Cs are practically non-existent. Ford and GM no longer use diesel engines in the chassis that typically are found on that size motorhome. Smaller units (Transit or Sprinter) are available with diesel as are the larger ones built on either a Ford F550 or Ram 5500. There are some used diesel E450 based Cs, but they are very rare, and on that particular chassis there is a minimal fuel economy advantage and no real performance advantage to a diesel over the gas V10. Now, before anyone flames me, I'm ONLY referring to the Ford E450 van cutaway, NOT the pickup chassis where the diesel offers a significant performance advantage.