1.6T if it's manual
2.1Tif it's auto.
I have a 5.4M cox craft, all up it weighs 1350Kg. i tow it with a commodore no problems and I have been to many ramps. It's a great size, can take 6 people and good enough to take outside. If you don't want to change your tow car, try and stay around the 1600kg mark.