On a Canadian gallon we never get less than 28 MPG if hilly country but on sleepy Vancouver island where speed limits are painfully low(50MPH is fast!!), we usually get at least 30 MPG.If you deduct 20% for bigger gallon we are getting about 24 or so regularly with our 20067(2007 build) Pleasure-way Plateau TS(I-5) engine; no dualies. lighter than later versions Diesel is currently a couple of cents a litre(say around10 cents a gallon) cheaper than regular gas. But remember, we Canadians, with huge oil reserves, pay way more per gallon than our friends and neighbours Stateside. Such is life. If one is buying a newer diesel or gas powered B RV it is important to note that the later models tend to get lower MPG due to heavier vehicles. Davydd's comments are relevent in this regard. It certainly beats the fuel sucking C RVs we had before...
AL