Roperteacher

I just filled up my truck for the second time today since I have owned it.. ( 500 miles). Dealer filled it up at the dealership but I topped off as I left so I would know exactly how full it was. Drove it all the way to where I had one quarter of a tank left.. HAND CALCULATED I got 21.1 MPG!! Of course varying speeds the first 500 miles and no towing. Mostly HIghway and various speeds and some around town. My 06 5.9 when new ( SIngle rear wheel) got 18 then got up to 21 by 17,000 miles. THis one seems to be getting off to a great start! Anyone selse seeing similar numbers? The 07 is a 2500 and the 06 was a 3500 SRW, equipped identical.. ( Both 6 speeds but tranny is a little higher geared in the 07)...