Just wondering if anybody is towing around 12000 lb 5er and what mileage is with duramax. I drive 09 extended cab long box 2500hd.

 

Welcome to the site

Tony

 

12mpg maybe 13 if youre nice to it and conditions are favorable. Your speed is the biggest factor. Other factors will be, lifted, 4x4, tire size, a/c on, Auto or Manual trans, flat, hilly or mountainous terrain, wind speed and direction, elevation, etc..... You probably already new that though.

 

OH yeah, I forgot diff gear ratio also...........

 

welcome to db