Purchasing a used Tiffin--torn between 2 models!

So, the FRED gets better mpgs, but the fuel is more expensive (about $0.45 more around here)...maybe it's a wash?

Today at B&P in Baltimore
Gas $3.39@ 7.5 mpg= 0.452¢ a mile
Diesel $3.59@ 10 mpg= 0.359¢ a mile

Even at 45¢ more then gas a gal.
Diesel $3.84@ 10 mpg= 0.384¢ a mile :)

I went from a 6 mpg gas MH to a 10 mpg DP.
Difference pays for all my maintenance on the Diesel.
This info is for all the ones that say Diesel maintenance is much more then gas. Oil, filters etc.