MICK wrote: It's well known ethanol raises compression, but it's not the compression we speak of when we talk about race fuels.

I didn't realize I wrote "compression". Doh! I meant octane

but just maybe
M.F.D.B. wrote:E85 is pure grain Ethanol with an Octane of around 116 mixed with 15% (roughly) 87 octane. In the US we use the (R+M)/2 "pump octane" at which E85 usually shows 104-106 octane, which is 4-5 (approximately) LOWER than the rest of the would using MON. So in other countries E85 would be 110 Octane (roughly).
Really...you serious?
Black Stone drew samples from half a dozen(?) E85 retailers. ONE of them had a pump octane rating of 105 as you describe...ONE! This is because there are 3 classes of E85 fuel. And which one would you guess is most commonly offered? Go ahead MFDB, take a guess...
The first class you seem very familiar with. The second and third classes have considerably less ethanol and a higher % of piss poor commercial grade petro fuel.
THEY ARE ALL MARKETED AS E85!! There are no laws requiring them, nor do they give a rat's ass if you purchase shit E85 and blow your car/bike the fuck up! As there used to be a law requiring stations to inform you of ethanol blended fuels...they have no obligation to do so anymore.
Furthermore, E85 has
YET to become a standardized fuel here on our market. The R+M/2 method
DOES NOT APPLY to all E85 fuels...not just yet. As unfortunately proven by Black Stone. Nearly half(?) of their tested samples proved 90 or below.
Lastly, riders I know who are trying to take advantage of E85 are complaining about pre ignition (not pre det). Cooler range plugs and a plethora of TBC coated heads and crowns are being tried and tested. Not a big problem I foresee on our CR500s, but larger displacement, higher comp multi cylinder engines appear to be prone.
I'll end this by saying you're correct MFDB...but there's more to this subject than that little bit of sorry information you posted. You come off as only being educated on this fuel's best case scenarios
...have a good day now
