sneaky98gt
10 Year Member
It's not always horsepower - often it is throttle response, idle quality, drive ability, off-boost or tip-in power, power under the curve, etc. Granted, it's not always a huge difference that you can boast about your peak HP in your signature on your favorite car forum to get all the high schoolers with bolt ons to adore you, but if you have a built motor/power adder/fuel system/etc,etc,etc build (read = $$$) and you are not willing to invest certain moneys to protect your investment, you're a fool.
I'll preface this by saying that I know very little about E85 and such, and I'm asking these questions to learn, not to be a jerk or anything.
I guess I'll ask the same question again. The difference in those things you mentioned, is it significant? Going from E-0 to E-10 doesn't seem to negatively hurt every car on the road (including 'performance' cars) except in maybe fuel mileage. I suppose going from E-85 to E-75 may not be comparable to going from E-10 to E-0, but I don't know that for sure.
As for the octane rating that you mentioned in post #16 above, the reading I've done suggests that the difference in actual octane (which is small anyways) doesn't make much significant difference in the knock protection; it's the cooling effects of the ethanol that do that, and E70 is every bit as good at that as E85. The difference in effective octane is, at most, a degree or so of max timing on a high horsepower setup. Correct me if I'm wrong.