100 miles less is like 12 mpg - that sucks.

 

Good catch, i was thinking E85

 

Thats why I love Cenex 94 octane. It's the only 94 octane Washington State has, and it has 10% ethanol to boot! It always has a higher knock resistance than the local 92 octane and some have said it's really 95 or 96 octane (although I don't believe them because they would have to test it).

Of course I can literally watch my gas needle dive because I do go through it a lot faster than regular 76 or something.

 

More smiles on your face - Priceless.

 

I've noticed IDC don't change when temperatures swing from 70 to 40s, so it makes me wonder if there is any temp compensation at all.

 

There is intake temp compensation for sure. I have seen it in action at the track.

Richened up the fuel mixture by 1 full point at a 95F+ track day.

This was with a open filter. Since then I added in a hacked stock airbox and the temp compensation isn't as brutal on hot track days anymore.

 

Really? Cuz I just tested my gas mileage with evoscan v2.1 and it confirms my 'tank-to-tank' data and I get an average of 25.11MPG highway and 21.97MPG when averaging city/highway trips. Thats exactly what I get when I track my mileage per tank....with E10 93 octane. So, your issue is isolated to your car and not the 'rule'. Considering that I am losing roughly 1mpg, I think thats "minimal" IMO.

You my friend have serious tuning problems if your comment is true.

 

The car was bone stock. The tune was from the factory. I have no reason to lie, so there should be no question of "if" my comment is true or not. It's not like I'm getting paid by the oil companies to say that straight 93 octane is better than watered-down 10% blend.

 

You are by far NOT the norm, but an exception. So please dont speak out like everyone who switches to e10 will lose 100 miles per tank because its 100% false. I'm speaking craziness here, you are the one with the car problem if you lose 100miles per tank switching from 100% gasoline to E10. Now if it was E85, thats a different story all together.

You might very well lose 100 miles per tank, but its YOUR car that has the issue. The average Evo owner will NOT see such extreme differences. On average you can roughly expect a 5% decrease in gas mileage. E10 produces 96.4-96.6% the energy of gasoline of the same octane so you will definitely need to use more fuel for the same energy level but not by a whole lot.

If anything I'd check or replace your front O2 sensor or figure out what's making it dump gobs of fuel into the engine when running E10.

 

The sudden increase in 10% (or less) must be a govt encouraged introduction to ethanol to the consumer or something. Might have a small profit margin for industry too, but most importantly I hope the added ethanol is not a procedure to to bring less refined fuel UP TO is labled octane claim, in this case 93. Shouldn't 10% ethanol bring the antiknock index to at least 94 octane when it's added to gas of 93 octane quality in the first place?

 

Well, the #1 reason E10 popped up all over the US in the past year and a half was because they had to remove the MTBE additive because it poisons the water system quite severely if it is spilled or a gas stations tanks spring a leak underground. E10 has been in the US for almost a decade, just in limited locations. Before, a lot of stations had the "contains up to 10% MTBE" stickers on their pumps (if you ever noticed since it might not have meant much to you at the time)so there has been a 90/10 mix for a lonnnng time. In a pinch, they just decided to quickly replace the harmful MTBE with ethanol since it was already an active product and similar in octane rating. The difference is that MTBE creates more energy than ethanol and is closer to pure gasoline. If they add any alcohol fuel to the gasoline, they will lower the octane of the gasoline portion (90% in this instance) so the mixture still produces the same octane level.

They don't just add 10% ethanol on top of 93 octane, as I explained a few posts back. That would be a waste of their money and we all know how the oil companies are,lol. whatever the octane rating is on the button you push.....is the octane you get, no bonus' there. Don't you think that they would slap a 94 or 95 octane sticker on the pumps and charge you more for it? I know I would if I were them!


Unfortunately, air/fuel mixtures, octanes and alcohol fuels are a very mis-informed bunch of topics online. Usually its all from "well he said..." or "my friends friends, sisters cousins uncle told him that..." which spreads a lot of false info and myths. Alcohol fuels are our near future and actually a good thing for us boosted fellas so I would strongly recommend taking some time and finding some reputable info online and keep yourself informed and up to date because there will only be MORE alternative fuels in the near future

 

I still wanna see some proof from you that they rate the octane after adding ethanol. I feel like that wouldn't make sense and they rate the octane before adding the ethanol. While i see your point about oil companies trying to f..k everyone over, this may not be true.
One thing is i don't even know if they officially rate the octane of ethanol. I mean when you go to an E85 pump or if you buy E98 they don't advertise its octane.

 

Let me dig up all of my saved liks for you. I have a lot over the past few years so I'll post them as I find them lol.

I found this one which is about gas mileage gasoline vs ethanol blends

http://www.ethanol.org/pdf/contentmg...yStudy_001.pdf

 

Thanks for the info Jamie.

In this case I'm not wasting any money on this crap when I can find more economic fuel elsewhere. I already use a more potent antiknock alcohol anyway.

 

Jamie, you've hit the nail on the head. I could add more, but it wouldn't really contribute to the ecuflash concerns. As most of you know, ethanol is a very influential, multi-faceted and controversial topic. Here's a little equation for the uninitiated:

(% gasoline/100 * Base gas Octane) + (% ETOH/100*115)= Final Octane

- assuming AKI for ETOH is ~115