Total thread jack here but have to tell you my replacement T-Reg was put to the test last weekend to Norris. Average towing MPG was about 14-16. If you pedal it in the mountains was running in 8th (yes 8 speed tranny) downhill running at 1900 RPM's 79 to 80 MPH at the base of the hill, drop to 7th as I am starting up the hill, jumps to 2400 RPM's and power to the top of the hill at 70 MPH. Totally breathtaking and never had to go below 6th gear or 3000 RPM's even if someone was in the way on the downhill, to keep running at 70 on the uphill. All while running AC and from a 6 cylinder diesel.
Personally, I will never go back to a gaser for towing, this little turbo diesel is a beast, you can physically lug it at 1800-2000 RPM's using the manual shift. I played with cruise a bit, while you can run this way, it is late and shifts too much.
Go Diesel my friends... Why on earth the US market does not wake up and offer it on a 1500 PU is beyond me.
By the way, my average non towing combined is 30 MPG if you keep your foot out of it, and trust me it has breathtaking acceleration for a 5000# vehicle.