Hello and thank you for using just answer. Mileage is not a factor for towing capability. This is a GREAT tow vehicle, I have used these to tow large boats and car trailers in the past. The maximum GVWR is 6470 LBS. curb weight on this vehicle is 4751 lbs.
The maximum towing capacity on your vehicle is 5000 lbs. A web site you can use to pull some technical specs. on your vehicle is http://www.kbb.com/, here let me pull your vehicle and provide a link:
I would recommend you check all fluid levels and be sure the brakes are thick, brake pads wear quickly on this truck when towing. See this download from your owners manual:
DOWNLOAD -see pages 125-128. Sounds like you are within your limits here.