2012 TDI Sport. Zero tick marks down at 10,900 miles and first oil and filter. At 18,600 now, still on the full mark on the sensor, the halfway mark on the dipstick, on flat level ground in the garage.
2013 TDI Sport. Full on sensor at 1500 miles when I started trailering, lost 2/8ths trailering 1050 miles to west yellowstone. Drove around Yellowstone for 18 days, and 700 miles, still 2/8ths down, drove back 1050 miles, and was 4/8ths down when I got to Las Vegas to fill up, another 250 miles or so to get home. Added a full liter, did now show "overfilled" I've put about 6-700 miles on the Touareg since the end of September. Too soon to tell how much more it will burn before 10,000 miles, but I went through 4 clicks and 1/2 a liter for sure in 2100 miles of towing. I towed about 6000 miles on my first 10,000 on the 2012,, same trailer, same type of trips and elevation gains, and never lost any appreciable or measureable amount. The 2012 gets on the full boost of the turbo a lot sooner than the 2013 does. That might be a consideration.
Know for certain that while trailering, I was on the boost the whole time. Trailering a 8 foot by 7 foot high wall and dragging it through the dirty air behind the Touareg is a major load, full time on the Touareg when doing 55 to 60 mph, all the time, even going down hill.