I use a Rand McNally 7730 with Life time maps that are free update. This is my second unit in 10 years and I have had great results with this unit. The unit will allow you to switch between RV and non-RV. In the RV mode this will allow you to enter parameters such as height, weight, total length, NO. and size of propane tanks, no U-turns and non dirt roads and so forth. So, far I have never been directed incorrectly when using my Rand McNally GPS. This unit will warn you of state boarder crossing, tolls, low bridge height and over weight on bridges.
2016 34RL CC; 2008 Ram Mega Cab 2500HD, 6.7L, 68RFE 6 speed, 4X4, Smarty S67, TDR 135K+miles