I'm averaging around 13-14 right now Mike. Yes it's down and I'm on my normal routine right now like I was with my LBZ. I was at least 15-16 on my LBZ with a 500RWHP tune.
I'm going to make the assumption that it takes a good 15k+ to actually get some decent numbers. I know the LMM guys were pretty disappointed but I thought the LML was supposed to be much better. Or so the hype had it...
I won't take any numbers as fact till they have 25k on the engine, then they're probably not gonna change from there. Our new 'Burb just got 13 MPG on the first tank, but I'm not gonna really track mileage till 2500 miles or so, once everything is seated and I get all the break-in fluids out.