The desktop dyno is probably pretty close, and the 450 hp number would be with something like "out-of-the-box" heads. As for the ethanol questions, this isn't exactly the place to discuss this, but the literature on E-85 is full of half-truths and lies. I made my change to E-85, as E-100 is not a legal motor fuel (unfortunately). The loss of fuel economy is experienced in an engine that will not run as well on E-85 as it will on gasoline. Cylinder pressure is the key, and many stock engines from the manufacturers do not make the cylinder pressure necessary to efficiently burn this fuel. If I optimized my setup for this fuel, by altering the camshaft timing, or raising compression to 12:1 (if it was wearing aluminum heads, 14:1), the fuel economy and power would both improve even more. An efficiently-running engine makes better fuel economy, no matter the fuel.
