My LMM pulled the camper pretty good, better than my old F-350. It got about 8-10 mpg depending on the terrain. I set the cruise on 65 most of the way and just let it go, although I did try 70 a couple of times but the mileage fell a little.
The turbo gage line blew in two coming up Sam's Gap on I-26, was running less than 30 psi, so we stopped at the rest area in NC & fixed it, it made it to about Asheville and blew again so I just ran the rest of the trip without it.....those cheap lines ain't worth a nickel, gonna get a good one tomorrow and fix it right.

How about a picture of your rig and trailer?

Iam going to pull my 15,000 lb 35 ft fiver 600 miles each way to Nor. Cal and back over the next two weeks and i wll let everybody know. I can tell you that the Banks system pulling the trailer around town for a few test drives is FRICKING GREAT! That mileage was 9.6 -10.5 hand checked.

Good to hear it towed well. Yes those plastic lines are junk. I often just toss them out and install some nice copper tubing. Works mint and lasts.

EDIT> Very nice truck, combo picture is needed.

http://www.dieselplace.com/forum/garageimage.php?do=full&p=56922&d=1204254933

Got a couple of pics here, it was getting dark so they're not very good.
I put the new poly tubing on at the beach and it was fine until I hit I-95 in Florence. The heat transferring from the turbo pipe to the fitting melted the new line. I just ran it home but I'm still wondering if that small hole could have caused it to lose some power, I don't think that small of a leak would but who knows?
I bought some copper tubing and fittings when I got home so now I've got the poly tubing 24" from the turbo pipe and I'm hoping that the heat won't make it that far.

Nice rigs. Here is ours.

Looks good.
I wanted to put a hitch on the back of mine and pull my 6 X 12 enclosed trailer to the beach but I was afraid I'd get caught in NC since it'd be over 65'.
On a side note, I didn't like the integrated trailer brake control at first. I'm used to just barely touching the brake pedal and use the trailer brakes to slow down a little but the ITBC doesn't work like the controllers I'm used to. I did get kind of used to it by the time I got back home though but I'm not sure if I'm going to leave it on or install my old one before I pull again.