I'm getting about 40 towing a 1250kg (fully laiden) van in my Golf. It's a 2.0ltr Tdi GT Bluemotion model.
When not towing getting 70+mpg on motorway runs - careful right foot acheives this at average 70mph even with some traffic. Am getting 50+ around town.
A good 33-35mpg towing, around 50- 60mpg solo depending on road, did get 37mpg towing on German/Czech motorways using ultimate diesel. 2.0TDi 138Bhp. Only a light’ish caravan MTPLM 1,230kg. The Haldex system puts most power to the front wheels for fuel economy, then transfers power to the rear wheels when needed.
Freelander 2.2 hse diesel towing a swift sport 585 fully loaded (1875) with 5 in the car I get about 27 MPG but going up hill 5 MPG :0 . at least I don't pay for the fuel ( company fuel card ).
------------- Loads of CC sites to many to mention.
Most people's view of MPG is pretty inaccurate as are many on board computers. The only nearly accurate way is to fill to the brim, hitch & tow a decent distance then fill to the brim again and work it out using old fashioned mathematics.
Passat and Laguna 130 tdi about the same - 32/33 mpg.