weight and mpg
I have a 2008 chevy 2500 HD 6.0 crewcab 2wd..3;73 rea rend, I tow a 10,000lb tongue pull TT right now and get about 8.5 to 9 mpg at 62 miles per hour. looking at a 5th wheel that weighs 13,000lbs when I load it out , how much is that going to affect my mpg? thanks for any help