In that 8,000 plus miles we take our "house" with us.
There is more than cost of fuel in traveling though our fill-ups are usually $75 or more to take us 400 mile down the road. Our overnight stay cost is where we save. We probably average about $5 per night from 0 to $35 in range. We also save on food with a full kitchen on board so we eat out while on the road not much more than when we are at home.
Most importantly in two months we visited 6 national parks, 6 national monuments, numerous state parks, museums, arboretums, events, parks, historical homes, caves, migrating sandhill cranes, etc. We rallied with two different groups in Arizona and Illinois with Class B camper vans and I attended my 18 consecutive yearly high school reunion. We met a lot of interesting people in campgrounds around the country. Surprisingly a lot of people on the road fulltime. We stick mostly to the blue highways. Only 6% of our travel is on Interstate highways. We drove the most challenging mountain passes we could find. We even managed to get on the Indianapolis 500 Race Track and cross the famed brick finish line.