[88Racing]

Jack,
My specs for the truck are this:
3.73 gears
4x4
5.4 3v with cat back exhaust/tru-flow xdi cai
Lariat
2006 with 22k
Weekend trip truck

For instance;
Around Sioux Falls 11.5-13 mpg
Mixture of driving on 87oct straight.
From 25-75 mph
10.5-12 89oct e10 blend

Went on a trip this last summer:
Started in sf with full tank of 87oct
Averaged 13-15 mpg to Tomah WI
Filled up there, with their 88oct
(did not see blend sticker)
Averaged 14-18 mpg to Springfield IL
Filled with 87oct
Averaged 16-20 mpg to Ohio

The whole point is the further east I went the better the mpg until after Ohio.
Coming back the same data was collected in reverse.

True I was not probably hammering down on it like I was at home. Kept it around the same speed 65-75mph.

So right there adds a little to your conclusion also Jack that states probably do blend gas differently.

Now f150 owners around here with 3.50 gears get 1-2 mpg better in town and 17-21 mpg on highway. The down side of this gear when they tow is they are back down their with the 3.73 mpg. Now I tow with mine and I have consistently the same mpg as long as it's not a high profile type trailer.

-Lars