MPG data on highway
I've never been concerned with MPG in the Postal, if I really cared, I wouldn't have done most of the things I've done to this point.
Since I knew I was going to have basically straight highway mileage for a couple tanks on the trip to the 2010 SOA national, I figured I'd see what the 4.0/AW4/4.56/35s gets
So far I've done four fillups on the trip down (not all full tanks) and here's the damage (BTW, I also knew I'd have a GPS in the Postal for the first time so I could verify that I did the speedo gear in the tcase correctly and it's within one MPH or so.)
One thing to note is that this is with the Jeep loaded with gear/tent/beer and I have the soft top and doors on, but both door windows were unzipped and the rear window was rolled up (for ventilation)
12.20 (I was really moving coming down through MI, drivers there know how to drive and traffic was moving around 80)
15.02 (this and the next tank were miles that were closer to 70 or so average)
15.10
13.62 (this was only about a 1/4 tank or so through some really hilly country coming into Cookeville)
So 13.99 overall, though the last one really isn't comparable driving to the first three, but it's so little gas that it only makes about .2 MPG different.
Better than I thought it would be!