I didn't baby it, pulling a 5,000 trailer is pretty arduous.
But I ended up just now buying a '17 gas powered Touareg. I parked my diesel rather than take a chance that something expensive would break. Or that it would leave me, and my trailer stranded in the middle of nowhere.The gasser is great, pulls the trailer just fine, but....But rarely gets out of 6th and spends much time bouncing between 4th-5th and 6th. Gas mileage at 70 mph with the trailer is 9 mpg, it was 11.5-12.5 in the diesel. And the diesel was mostly in 8th, that big wave of torque just muscled it ahead.
When not pulling the trailer, mileage goes up, of course. To maybe 21-22 mpg at 70 mph. I never got below 30 mpg in the diesel at 70, and had some 36 mpg trips. The gas engine is more responsive and no turbo lag. Much easier to find a vacant gas pump than a diesel one as well.
If I had my druthers, tho, I would have kept the diesel. The newer Touareg is a Wolfsburg edition so it is more luxurious than my base diesel, and has more safety features: adaptive cruise, lane change warnings, better sound system, air conditioned seat cushions, heated steering wheel, etc. But the whole experience is 95% the same.