I had a 2015  petrol and towed a 1900kg Jayco poptop 180 ball weight. I towed it to Cairns and back to Victoria, about 10k in total. I kept a log on petrol used and it came out at 16.11l/100 at the end of the trip. I put air bags in the rear and run them at 20psi for the trip vut not when towing but then I liwer them to 10psi. The car towed it extreemly well using performance mode gear.  You have make sure you get the weights right at a weigh bridge.I loved it but unfortunatly it was written off this year.