I'm in the market for a used F450-F550 for the purpose of converting to an overland camper for travel globally. My understanding is that all diesel engines manufactured after 2007 require low sulfur diesel fuel? Some people have mentioned that not all countries have low sulfur diesel and that low sulfur diesel engines will have problems with their fuel. I'm just trying to decide whether to buy pre-low sulfur diesel or not. Correct me if I'm wrong here.