Yea, pre i think 13 gm's weren't tuned for e85 and made same or less power and fuel economy sucked on it, a buddy tried it and got 7.5 instead of 11. Gm so far has been the only smart ones in tuning for it.
On my yota I have ran live data on different fuel octanes and premium is the optimum, others that have tried e85 in their flex vehicles had bad results, just like my buddy in his older 5.3 gm power was down seemed sluggish and worse economy.
If everyone would jump on it in the tech dept maybe they could actually make some people use it and put all those gvt subsidies to good use lmfao.
Only thing good about my flex fuel truck is that I can tell how much ethanol % is in the fuel, and it saves me about $6500 as I can't slap on the factory s/c kit. hahaha.
