Towing 2003 Explorer 4WD With 6cyl MB Diesel

I am hoping to contact someone who has towed an Explorer or other 4,000+ weighted vehicle with the same setup we have. My Sprinter 3500 has a tow hitch rated at 5,000 pounds and my Freightliner/Sprinter 3500 user manual lists maximum towing weight as 7500 lbs. The Explorer is just over 4,000 pounds. So... The question seems to be simply whether the towing experience would be a problem because of the smallish Mercedes diesel engine. We don't mind slowing down when going up grades or in mountainous regions. Please contact me with your experience if you have done this or advise if you know this is not advisable. We need to make a decision soon as to whether to invest in towing the Explorer four down.