well, methanol is closer to 115, or 125 ron. e85 is closer to 100 -105. most fuel is a mixture of chemicals. e10 has been around awhile, which is the mixture you saw. nothing new.

as far as running it in your car, you don't have to do too much. the faq has alot and wikipedia does too.

 

ethanol is around 112 octane. e85 is like you said, 105ish. but i do not suggest running e85 in your car yet, unless you are good at tuning cars, as most pro tuners will not touch it yet. Running e30 is fine even for the stock ECU, it can learn the timing increase to make the car run very well.

*just for anyone who is confused, e85 is 85% ethanol 15% gasoline (hence e85) when i say e30 i mean 30% ethanol 70% gasoline (which would be 35% e85 and the rest gas). I had a hard time following this part when i first started reading the FAQ

 

Sorry.....I meant e85. I assumed thats what we are talking about when refering to ethamp;. Straight ethanol is a bit different. I have only heard of full race cars using it

 

yeh i knew thats what you meant, but i thought i'd clarify incase anyone didn't fully understand e30 thinking they sold it that way, or that it was completely different fuel.

no tune for meth is just as useless. but your stock (or reflashed) ecu will learn e30 all on its own.

 

Funny enough, I was just reading some of the E85 FAQ today. Looks like you can use up to a 30% mix of Ethanol and gas (I guess 93 octane) with no problems on a stock ECU tune. People have been running 100% E85 with upgraded injectors for over 2 years on OEM fuel system parts with no detectable wear, corrosion, or problems other than one guy's fuel pump died because he was running 80psi fuel pressure.

In essence, they say to start with a low % mix, then slowly up the % until you are happy with the performance, or you throw the "System to lean" code, meaning that the ECU has run out of compensation room on the closed loop a/f. At that point, you back it off a little bit.