Fuel blends E10 E15 E20

[BULL]

FYI, your "E10" might be more than that.

https://youtube.com/shorts/0u4_E60IRTk

 

[Speedy!]

My 170 says 11% on straight 93 around here.

Honestly if cars were setup for it a E40 would be a nice sweet spot.

 

[Jack_Toepfer]

So if I get e85 at the pump, what’s the octane of the gas they’re diluting the e100 with?
For example, to make e40, I’d use “e85” + some amount of e10 gasoline… does it matter if it’s 87 or 93?

 

[Speedy!]

My buddy who worked in oil and gas says E85 isn't cut with gasoline but "some hydrocarbon"

 

[Jack_Toepfer]

That explains the 33% loss

 

[Speedy!]

You probably know this, but just in case alcohol has less energy per gram than gasoline, about 30% less as it turns out. So it takes 30% more volume to get the same bang out of it. Benefit is more volume means cooler, but you do lose mpg.

 

[2ndAmend]

Local 93 and 94 shows up as E9 in the 170.

Next week I'm driving 40mi into MA to get some E85, which has been reported to actually be E72... For most people that would be a good thing... But adding E72 to a near empty tank I might end up with less then optimal E content...

 

[vortecd]

Strange how it is all somewhat different everywhere. In the winter we have e75 and summer is e85. With current gas prices I'm just below (28%) less for that 30% more use. When gas is closer to $3 and e85 is $2 I'm over 45% savings so cheaper to run e85

 

[Jack_Toepfer]

You probably know this, but just in case alcohol has less energy per gram than gasoline, about 30% less as it turns out. So it takes 30% more volume to get the same bang out of it. Benefit is more volume means cooler, but you do lose mpg.

So if it’s only 85% alcohol we shouldn’t lose the whole 30%, since the other 15% should be gasoline. Because it isn’t, we only burn 85% of the gallon at 30% of the energy…

 

[jgilj]

Local 93 and 94 shows up as E9 in the 170.

Next week I'm driving 40mi into MA to get some E85, which has been reported to actually be E72... For most people that would be a good thing... But adding E72 to a near empty tank I might end up with less then optimal E content...

Perfect! 72%

 

[jgilj]

My last tank is showing E79

 

[Speedy!]

I think technically speaking E100 would be a 33% decrease in mpg so E85 is a bit better than that and most accept 30% as the number but ymmv as the saying goes.

 

[zhc]

Honestly if cars were setup for it a E40 would be a nice sweet spot.

My buddy who worked in oil and gas says E85 isn't cut with gasoline but "some hydrocarbon"

So if I get e85 at the pump, what’s the octane of the gas they’re diluting the e100 with?
For example, to make e40, I’d use “e85” + some amount of e10 gasoline… does it matter if it’s 87 or 93?

E40, if it's cut with decent gas/hydrocarbons, would be great. It could easily be over 99 octane. However, if they're only aiming to achieve 93 octane with an E40 blend, they'd only have to cut it with something as low as 84 octane to get there. On paper, E40 that's only 93 octane wouldn't be any better than E10 or E0 that's also mixed to achieve 93 octane. Btw, I'm not aware of any sort of legal or consumer protection agency that requires ethanol blends be of a minimum octane. I imagine the "minimum" is whatever OEM tells them their flex fuel cars "require" but none of that is regulated.

 

[zhc]

Next week I'm driving 40mi into MA to get some E85, which has been reported to actually be E72... For most people that would be a good thing... But adding E72 to a near empty tank I might end up with less then optimal E content...

I have nightmares about running fuel that's only testing at E70 at the pump because I just don't know what the gasoline portion is. For example, if it's primarily 60 octane Pentane, the resulting octane of the mix based on simple calcs would be about 95 octane. Cut that ethanol with 93 octane fuel and the resulting mix is over 105 octane. Why does this matters in your case? The D170 OEM cal starts adding timing above 10% ethanol, by 50% ethanol it's giving you 65% of available timing and by 65%, it maxes out. The quality/octane of the fuel could make or break here. If it were me, I'd carry E98 or X98 with me to cut the fuel back up to at least 80% or higher or run straight 93 10% octane so the D170 flex logic runs what the OEM has deemed safe for 93 E10.

Here's a fun little calculator that you can play with, scroll down to the advanced calculator.

MPT Performance E85 Ethanol Mix Calculators

Here were some of my conservative assumptions. You'll get different answers depending on who you ask or what your sources are for this info.

Pure Ethanol Octane AKI Octane 112
E85 Octane 105
Pentane Octane 60
Pump 93 Octane 93

 

[Speedy!]

The issue with the 170 and 93 octane is 22psi of boost and 4deg of timing at wot. Makes a lot of heat like that so no wot for me unless E40 and above. You can really feel the car laboring at any load and 93.

I've been meaning to ask Wilder why they didn't tie the bypass to E%.

We've got Speedway E85 here and I've always had good results with that. Smells like moonshine.

 

[zhc]

The issue with the 170 and 93 octane is 22psi of boost and 4deg of timing at wot. Makes a lot of heat like that so no wot for me unless E40 and above. You can really feel the car laboring at any load and 93.

I've been meaning to ask Wilder why they didn't tie the bypass to E%.

Yea, there's no timing so that's why it feels labored on 93. They've tested it though, it survived their torture tests. Personally I'd avoid wot in general but you have to have some faith in their process. The thing I'd worry about is the actual octane of the fuel itself, whether it's sufficient or not for what the D170 tune expects at whatever ethanol % it's reading. That part is variable. As you friend said, they cut ethanol with hydrocarbons and there's a lot of different types that vary in octane and costs.

Why not tie the bypass in to reduce boost? The time/cost to make programming changes likely was too high to implement has been my guess. It's not an easy/simple change.

 

[zhc]

So if I get e85 at the pump, what’s the octane of the gas they’re diluting the e100 with?
For example, to make e40, I’d use “e85” + some amount of e10 gasoline… does it matter if it’s 87 or 93?

Those are two very different questions from my perspective.

If you take E98 from a pale, you can mix it with whatever you want. You can mix it with 93 and get a very high quality high octane blend all the way down to 40%.
If you get E85 or E54 from the pump, what they cut that ethanol with is unlikely 93 octane. Your guess is as good as mine. I haven't been able to find any reliable information about it to answer but I have observed instances where octane was questionable in something testing at 60 or 70%.

*Edit* I reread your question. Yes it does matter if you blend down with 87 or 93. If you use a lower octane, it will lower the end resulting octane rating. Does it matter so much that you need to worry about it? Well, that depends on what you're trying to achieve. If you're setup doesn't need a lot of octane to avoid knocking, then no, it doesn't really matter. If you're trying to get as much octane as possible because your setup needs it to not knock, then it does matter, a lot.

 

[Speedy!]

Off topic @zhc but have you seen the new 170 tune Dodge released last week? Apparently letters headed to owners letting them know. Updates look interesting.

 

[zhc]

Off topic @zhc but have you seen the new 170 tune Dodge released last week? Apparently letters headed to owners letting them know. Updates look interesting.

I haven't seen an updated tune yet. Some changes may not even be visible to us using tools like HPTuners. Hopefully it works to resolve some of the issues that some folks have been fighting at the drag strip while being on an OEM calibration.