Hello agin all I have recently switched back to running E 85 ethinal in my 2005 gmc Sierra 1/2 ton with the 5300 v8 flex fuel engine. with lower gas price now e 85 price has drop sharp to with a current cost 0f $2.07 per gallon. I am very supprised at the diffence of power with the E 85. With my foot in the gas at 3/4 down to the floor getting on the highway with E 85 is almost the same as my foot all the way down to the floor getting on the highway with regular gas. as far as gas mileage gose I get about 1 mpg less with the E 85. Eny way just wanting to know if enyone els runs E 85 in there 5300 flex fuel GMTs thanks hope to here back from you all.