Price of E85 vs. Gasoline: A Matter of Percentage

Basically, this article is making the point that a set dollar discount for E85 is a better deal as gasoline prices go lower because that discount becomes a bigger percentage discount.
The Minot Daily News: More than just numbers:
by Marvin Baker -- 12/24/2005
"'Remember, 70 cents off at $3 per gallon was a 23 percent savings,' Satrang said. 'So, if gas is $2.20, you need to save 50 cents to be 23 percent cheaper. If your mileage drops 23 percent, you break even. If you can buy E-85 23 percent cheaper, you can afford to lose 23 percent mileage and you would still break even.'"