MPG drop from 30 to 13.5 with 4k lb trailer
Hi guys, new here, would like to get some input from you guys and just to confirm if these readings are normal. I have a 2013 Cayenne Diesel that I just took on a 3000 mile round trip to pick up a toy hauler, Coachmen 17blse rated at 3700lb. So my first 1500 miles to the dealership turned avg 30mpg, on the way back with the trailer I hit avg 13.5. IS that normal for 3700lb toy hauler??? I mean thats almost a 60% drop, how is that possible? okay add some water in there, the thing is 4000lb max. I can still live with 13.5mpg but just don't understand how it decreased by so much, any inputs appreciated.