I have noticed one thing not mentioned in the poll. In the summer months I typically get an average MPG (60% highway) of 17-18. However wintertime sees this drop considerably to the 14-15 MPG range. I assume this is due to the greater amount of "cold weather additive" used to keep diesel moving in the cold weather. Unfortunately for diesel owners here, Diesel is also at its highest price during the winter (competing with the fuel oil market). No big deal but my old 6.5L chevy never saw this big a drop summer to winter.