2013 Volkswagen Touareg TDI sport w 255-55-18 wheels.
You know when I am towing, check our the Sept 2013 portion of my fuel logs, and you know when I am empty. Usually tow at 55-60 MPH, 14" tires limit my speed.
21 foot 3800 pound TT empty, probably at 4300 -4400 to tow.
2013 Touareg Sport TDI fuel logs, towing and un hitched. 4200 miles of history.Sometimes, I really know it when I got a crappy load of diesel on a fillup. The MPG's fall off 10%, doesn't matter if it's my TDI Touareg or my TDI Passat. I try to avoid Shell diesel fuel here in California, and Valero, those two seem to be the worst offenders, and have been for the past 10 years. My fuel logs every fill up don't lie.