2005 Newmar Dutch Star 4010- Update

I had a cat 330 hp engine in a 39 foot winnebago. Now have a Cummins 400 in our current 39 foot coach. The cat was quicker "off the line" with very little or no turbo lag. The lag on the Cummins was tough to get used to. I would get 8 mpg, sometimes 9 and less frequently even 10mpg with the cat. Now with the Cummins I get 7 to 7.2 mpg. Seldom varies. I have never thought I went up any hill faster with the 400 Cummins than I did with the 330 cat, but I do go up the hill in a higher gear, just not faster. I like my cummins, but liked the cat, and some things about it better,as well. I would never buy a motor home based solely on a few cubic inches and manufacturer. The biggie is floor plan and coach manufacturer.