Well, I have only checked mileage on two tankfuls when I was on the first trip. I was
a little shocked to see we were getting a bit over 13MPG while pushing into a steady
30 or 40 mph headwind on the interstate in Kansas. Neither of us could believe it, as
the wind was constant and on our nose, and I was really pushing the UNIMOG into it. One reason we checked the mpg at that point was to see just how lousy we were doing, given the conditions, the revs and the stellar UNIMOG aerodynamics...We checked and double checked, and then did the next tankful to be sure, and there it was, about 13.3 MPG. Crazy.
Eventually, we got tired of battling the headwind and it seemed Kansas was taking forever, so we took a right and made it a sidewind as we two-laned it up into Nebraska and then Colorado in short order. The side wind did not move the UNIMOG around, and I was able to back off on the revs as soon as we made the turn.
I haven't bothered to check the MPG since.
As far as the Exhaust brake, are you sure you don't have one? I thought they all did,
but the more I learn, the more I find they can have all sorts of different options. Yours is newer than mine, so maybe yours turns off with the key, but with mine, you can take the key out and ,aside from the dash lights, the UNIMOG doesn't seem to care...
It is the little White (in my truck) button on the floor, just where your left foot would come to rest, if you weren't "trained " to avoid it. It is the Engine-killer/exhaust brake, and (on mine,anyway) you can't use it until the air comes up, meaning that the first time you start it in the morning, you are making a commitment, so check for innocent bystanders, as you can't really kill the beast until the compressor gets enough air going, unless you dump the clutch in a low gear which is not a good practice....
So, while cruising at high-ish altitude south of Casper I stomped on the button,without knowing it,while also standing on the gas and it lost power, sorta sputtered and scared the heck out of me.
The UNIMOG was running really well, the air was cold and I was having a great time
then all of a sudden, brrrrddddddd...I clutched,shut it down and coasted to a stop (one REALLY misses the power steering as soon as it is gone), and I really thought I'd blown my new baby up. It was a dark moment....but after a few minutes, after checking it all out, I fired it up and it was just purring....checked it out some more and continued on to Casper. I put my case before the mailing list brotherhood via the internet, and they (KAI, MARK,ROB,RON,BEN,DARREN,CHRIS and others) went out of their way to offer diagnostic help, hauling services, etc etc.I checked it out all the next day,changed the oil,prodded and poked and came up with, in the end, nothing was wrong, except for me,the clumsy driver and it has been fine ever since. The amount of help I received, without knowing anybody on the list was astounding...I think KAI must've called me in Casper from San Diego 4-6 times, each time telling me new things to check; it was an amazing level of support, better than ONSTAR, for me.
Anyway, sorry for being so long-winded.I'll try and watch that...