Ruben, I guess you have already tried to tweak your settings ?? I notice with my current Garmin, as with my previous Tom Tom 130, if I have the shortest route setup, it would take me back roads. If I have them set up to quickest route, it would take me mostly interstate and primary roads. My current Garmin now asks "do you want to take dirt roads (or something like that), if they are included on my route.
Chap , DW Joy, and Fur Baby Sango
2006 Ford F150 Super Cab 4x4
2008 Surveyor 263