Don't know if it helps any but my 2003 Yukon is E85 capable and real-world mileage figures are about 17.5 mpg for RUG and 12.5 for E85. Don't know about E10 but you could probably interpolate the values.

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1983 M-B 240D-Gone too.
1976 M-B 300D-Departed.

"Good" is the worst enemy of "Great".