The nobby lugs on all-terrain tires are as seducing and misleading as that “just one more” shot of tequila. These tires do not change the fact that this is a van. A steep railroad crossing could beach these whales, let alone the rocky uneven terrain of the desert backcountry. The length between tires is called a vehicle’s wheelbase and sprinter vans have one of the biggest of 4 wheeled vehicles. That means it can get hung up on its belly easily and tight turns are out of the question. If a dirt road is washed out 10 miles from your last turn you are looking at driving in reverse for 10 miles. They also have high centers of gravity, so sharp corners and uneven terrain have a much better chance of tipping one over. They just aren’t very fit for what a lot of people think they are.