CRD or Di will be real slow going dragging 3T behind it. But it will do it. The CRD is more reliable than the Di, though the Di your looking at is 2006, its better than the older Di motors. As happy mentioned too about your tow limits. Make sure on whatever you buy can legally tow this weight. IF fuel consumption isn't going to weigh in on your decision, the TB48 4.8ltr would be my choice.