E85

So I’ve been doing some research and want to know what you guys think.

I’m in California and all we have is 91 octane and I’m on the tsp1. There is a gas station that does have e85 not to far from me. I’ve read that adding 10% ethanol to 87, 89 and 91 will bring the octane rating up 2 points. I know everyone will say to just do flex fuel but I'm gonna wait until after I do the clutch for that. I just want to see if I can do this to get the full potential of the stage 1 tune.

Is this a good idea for the time being to get “93 octane”? I did the math and I hope it’s right but I’d need about 1.4 gallons of E to add 10% more ethanol to a full tank.

I would recommend mixing in 1 gallon of E85 with your tank of 91 octane and seeing how that impacts your knock control levels.

That's what I do, I live in California. I first fill with 91 then drive to a e85 pump and put 1.5 gallons and it definitely helps the knock control or even better if the gas station has both pumps close to each other

I only use 93 octane.

Jes_si562 said:

That's what I do, I live in California. I first fill with 91 then drive to a e85 pump and put 1.5 gallons and it definitely helps the knock control or even better if the gas station has both pumps close to each other

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Awesome! They have them right by each other at the gas station. Is it a noticeable difference power wise?

silverblip said:

I only use 93 octane.

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I would if I could but we only have 91 so that’s why I’m asking about adding E to bring it up to 93 from 91.

Most gas in Calif already contains up to 10% ethanol. You’ll need to add 3 gals (E85) to achieve 93 octane and end up with E28, which really needs a tune. Maybe compromise by adding 1 to 1.5 gals of E85 to achieve 92 octane and stay below E20 without a custom tune/flex fuel.

http://www.wallaceracing.com/ethanol-mix-calc.php

TypeSiR said:

Most gas in Calif already contains up to 10% ethanol. You’ll need to add 3 gals (E85) to achieve 93 octane and end up with E28, which really needs a tune. Maybe compromise by adding 1 to 1.5 gals of E85 to achieve 92 octane and stay below E20 without a custom tune/flex fuel.

http://www.wallaceracing.com/ethanol-mix-calc.php

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What about mixing 100 octane with 91? They have it at that gas station too. I found a calculator take make it 93 and it says 9.6 gallons 91 and 2.8 of 100. Idk if that’s a good idea or not but that way I’m not going over 20% ethanol.

EkSean said:

Awesome! They have them right by each other at the gas station. Is it a noticeable difference power wise?

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Power wise a little difference but not much but forsure you can feel the engine run way smoother

EkSean said:

What about mixing 100 octane with 91? They have it at that gas station too. I found a calculator take make it 93 and it says 9.6 gallons 91 and 2.8 of 100. Idk if that’s a good idea or not but that way I’m not going over 20% ethanol.

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Your better off using full 100 octane but you know leaded gas messes up your cat

Jes_si562 said:

Your better off using full 100 octane but you know leaded gas messes up your cat

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Which one is leaded? E85 or 100 octane?

Jes_si562 said:

Power wise a little difference but not much but forsure you can feel the engine run way smoother

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That’s the first thing I noticed is it’s way smoother at idle and driving. I noticed a little power gain. Nothing crazy though.

Jes_si562 said:

Your better off using full 100 octane but you know leaded gas messes up your cat

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I have catted prl dp and that’s one reason I don’t think it’s a good idea to mix because it’s leaded. I was wondering if that might be a better idea than e85 but I’m just weighing my very little options haha.

100 octane

MuffinMcFluffin said:

Which one is leaded? E85 or 100 octane?

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P

I did more research and the Sunoco pump 100 octane is unleaded .

EkSean said:

What about mixing 100 octane with 91? They have it at that gas station too. I found a calculator take make it 93 and it says 9.6 gallons 91 and 2.8 of 100. Idk if that’s a good idea or not but that way I’m not going over 20% ethanol.

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Sorry, no experience mixing 100 and 91 as I've no easy access to anything higher than 91 around SoCal. I've added 1 to 2 gals of ethanol to a couple of cars with no ill effects. Yeah, I always blend below E20 to stay on the safe side.