My husband and I were looking at a 38' Jayco 5th wheel (40'4" actual length). Years ago, when all of our kids were at home and little, we had a 31' tow behind that we pulled with our Suburban, so we have done this before. I have a couple of questions: 1.) I know you need to look at the tow vehicle specs to see if the vehicle is rated for that weight, but what are the pros & cons to gas and diesel? The vehicle is going to have to be a 4 door (full second row seating as our 15 year old is over 6' ). 2) We live in the land of eternal wind, ND. Do you need a dually? 3) How do you figure the total length of your rig? Many state parks have length restrictions.