I was getting between 18 & 22 towing a 1250kg van with air on and in summer. I just did 310 k last 90k with air & towing 850k 310 knot 36.76 Ltrs with air on
I'm new to the forum, but having read quite a bit about getting only 16 ltr per 100 k, I started to see how to improve on this. After adding 2 easy add ons I'm now get 11.879 ltr per 100k. I'll post photos soon