30% mix - fueling experts chime in

[50BMG]

It will throw a code if the trims get anywhere near the car running lean.

I thought the same thing K4, but that's why I think he said "... you're relying on the ECU/Computer a lot". To wit, I think: Uh YEA! Don't we all!?! LoL...

I get that. If the car is tuned (stock) for E10, then going to E30 will cause the feed-forward lambda to be about 10% lean. The STFT works really quickly on these so it won't be lean for long. If it's a stock or Roush tune, it will pull timing in the meantime, though some tuners get rid of this protection for some odd reason.

Thanks Mike. I don't know exactly what all of those acronyms mean exactly, but I'm trying to learn. I really need to read more.
What is a easiest/best way to get my car tuned to run different levels of E if I want to? Should this be done in coordination with a "performance tune" as in one of those remote mounted tuning devices which can be programmed with multiple tunes inside so that I can run straight gas/E30/E50/whatever as fuel availability make change depending on how far I am from home (there are many E85 pumps in my home area, but that might not be true for anywhere I may road-trip to).

I MUST make a correction. I ran the tank dry. then added the 30% mix and drove it for a week.

STFT was bang on.
LTFT was around 15-16% (Previously I said 10%).

Still very acceptable.

Thanks Wildhorse. The first time I ran E30, I was coming off a road trip where I ran basically an E19 mix to get a cheap octane boost and I ran the tank down to very near zero before I did that 1st test.
I am also 2/3 spent on my 2nd full tank of E30 mix (93 octane gas & E85) right now, so I think the fuel that's currently in my tank is likely very "true" to the E30 ratio.
I know my car seems to love it thus far! That's only a seat of the pants assessment (which both my son and I notice) and semi-confirmed through the data using the cars Track Pack software.
I gotta get to the strip to see what she'll do!

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[engineermike]

@50BMG is your tune stock?

 

[50BMG]

@50BMG is your tune stock?

Uh oh.....
Yes, stock

 

[engineermike]

Uh oh.....
Yes, stock

My advice will probably be ultimately useless to you.

Im running flex tunes in both of my vehicles and they work fantastically well. Both use the factory flex logic, which is ridiculously capable if tuned properly.

The problem is that in order to make it work right, PCMTec must be used to create the tune. Hptuners, which is what most commercial tuner use, does not give adequate access to parameters to make it work right. Even still, the way many commercial tuners manage flex spark timing is unsafe, so I don’t trust any of them anyway. So what does that leave you with? Not many options…

 

[Angrey]

This will be a long post but I'll do my best to be succinct.

First, there's this misunderstanding out there that ethanol blends are all the same. The reality is, the E10 blend you get with 93 is different than the E10 blend you get with 87. Furthermore, much of the time, the "E85" blends you get are ethanol mixed with trashy 85 octane.

This has impacts on the octane ratings resulting from different mixtures of pump 93. What does that mean? It means that in certain parameters, it's BETTER to mix pure E85 with a higher ratio of pump 93 than it is to mix a lower amount of 93 with a low grade ethanol blend.

As you can see, blending quality 93 with trashy low grade ethanol blends (which have 85 octane as the remainder component) isn't always the best solution.

From the snippet of the chart, the red are eliminated as a reduction in total blended octane. The orange are highlighted as a "not really worth it" section where you're getting a slight octane increase but it's not really worth the brain damage and hassle of mixing your fuel.

The yellow are 94 octane (a slight improvement) but again, not exactly moving the needle. The light green is 95 octane where it starts to really create noticeable benefits worth the exercise. The solid green are 96+ where it's obvious those are meaningful and should be worth the effort.

Now let's examine the "limits" for an untuned system. If we set a 30% octane content as the max we should run without unacceptable fuel trim adjustments, the constraint shaded results with this:

If we eliminate these from the original table (or overlay) the result is this:

Lastly, if we evaluate these preferable areas to try to maximize the amount of octane increase and minimize the amount of total ethanol, we end up with this:

So what does that all mean?

Well, some obvious and not so obvious takeaways:

1) The meat or sweet spot of this is around the 50% quality 93 mixed with E50+ ranging to increased 93 ratio (up to around 80%) mixed with even higher quality Ethanol (up to 85%).

Once we examine how much octane we're getting with each combo compared to how much we're increasing the amount of fuel flow and trim adjustments, we arrive at the area where the best combo of upping knock resistance compared to the increase in ethanol % is around the 70-75% quality pump 93 enhanced with 30-35% of E75-E85.

2) Hitting this from the NEGATIVE side, running a quarter tank of 93 and the rest E30 results in a near unacceptable increase in fuel flow (beyond the 30% ethanol) with little to zero increase in knock rating.

Furthermore, contrary to popular misconception, having 90% of your tank quality 93 and splashing it with anything less than 60% Ethanol isn't really doing much. You're having to mix fuels and getting a very very small increase in knock resistance.

Case in point, 3/4 tank of quality 93 mixed with 1/4 tank of E30 does virtually nothing for knock resistance (from a chemical standpoint).

3) I didn't include any thermal benefits, so yes, increasing ethanol content even if it results in an even or marginal increase in knock resistance could be beneficial due to the reduced combustion chamber temps, but those benefits are more difficult for any of us to quantify and the question would loom whether it's worth the headache of blending or the potential drawbacks of running more Ethanol on an untuned setup.

 

[K4fxd]

Case in point, 3/4 tank of quality 93 mixed with 1/4 tank of E30 does virtually nothing for knock resistance (from a chemical standpoint).

That wouldn't equal a full tank of e30 would it?

E30 in the tank would require 4.8 gallons of alcohol and 11.2 gallons of gas. so off the top of my head 9 gallons of 91 and 2 gallons of 85 and 4.8 gallons of 105 = 94.6 octane

Which is damn close to your charts.

 

[Angrey]

That wouldn't equal a full tank of e30 would it?

E30 in the tank would require 4.8 gallons of alcohol and 11.2 gallons of gas. so off the top of my head 9 gallons of 91 and 2 gallons of 85 and 4.8 gallons of 105 = 94.6 octane

Which is damn close to your charts.

I'm not understanding your ?. 3/4 and 1/4 is the ratio. Doesn't matter if the tank is 1 gallon or 10,000 gallons.

If you mix 93 (75%) with E30 (25% by volume) and it's true ethanol (30% ethanol which is 113 and 70% 85 octane gasoline) the resulting blended octane is roughly 92.7. You've actually reduced the knock resistance of the fuel (again, because the filler component of E30 is trashy).

Now if you mix your OWN E30, you've changed the components.

The example is a bit obscure because you'd never get E30 out of the pump. But yes, if you create your own E30 with a higher quality gasoline component then the results would be better.

My point is, mixing with E55 or E60 from the pump, that other 45% or 40% is 85 octane trash.

If you create your own ethanol concoction using better gasoline and E85, you're only stuck with 85 octane being 15% of that mixture.

So in theory yes, you could cut/blend however you like, I'm strictly speaking to how it would come out of a pump.

 

[K4fxd]

Most will mix 91 or 93 octane gas with E85. Most 93 is actually 91 with E to make it 93. I also assumed the E85 to be at least 80% E and I used 105 for the E octane. If it is 113 then the octane is 96.8

So my above is using pump 93 with pump E85

Make sense now? If the pump gas is actually 93 with E added then the numbers are better = 98 octane

All numbers are a rough estimate. Mixing your own 30% is worth a octane bump.

If using VP or another fuel supplier E85, they do use good gas in the E mix and not the trash gas you get from the e85 pump

 

[50BMG]

My advice will probably be ultimately useless to you.

Im running flex tunes in both of my vehicles and they work fantastically well. Both use the factory flex logic, which is ridiculously capable if tuned properly.

The problem is that in order to make it work right, PCMTec must be used to create the tune. Hptuners, which is what most commercial tuner use, does not give adequate access to parameters to make it work right. Even still, the way many commercial tuners manage flex spark timing is unsafe, so I don’t trust any of them anyway. So what does that leave you with? Not many options…

Well, I had to read it slowly a couple of times to absorb everything, but I wouldn't call what you wrote as "useless" to me! I appreciate it all!

So, how do I get the same "flex tune" that you describe on my 2020 PP1 GT and, I'm assuming that PCMTune is software (or is it a pre-programmed software package?) which you put on a laptop and connect the laptop to the OBD port to allow you to fine tune different parameters of the ECU to make the E/Gas blends (at whatever level) more beneficial for Horsepower yield AND safety in terms of engine damage prevention.... Right?

 

[K4fxd]

So, how do I get the same "flex tune" that you describe on my 2020 PP1 GT

Either buy the software and tune it yourself or look for a tuner who uses this software.

 

[GregO]

Either buy the software and tune it yourself or look for a tuner who uses this software.

Who’s retail tuning with PCMTec other than Wengerd ?

 

[engineermike]

So, how do I get the same "flex tune" that you describe on my 2020 PP1 GT and, I'm assuming that PCMTune is software (or is it a pre-programmed software package?) which you put on a laptop and connect the laptop to the OBD port to allow you to fine tune different parameters of the ECU to make the E/Gas blends (at whatever level) more beneficial for Horsepower yield AND safety in terms of engine damage prevention.... Right?

What @K4fxd said. PCMTec gets you full access to tune whatever you want for $200-300. It's a software package and you have to get a dongle as well (part of the cost mentioned). It's really a bargain. But tuning isn't so straight forward and is definitely a learning process. I did a flex tune on a nearly-stock 2019 for a local guy and it works pretty good, but it takes some doing to get it done.

 

[robvas]

Who’s retail tuning with PCMTec other than Wengerd ?

Lund?
https://lundracing.com/pcmtec-multi-tune-upgrade

 

[WildHorse]

This will be a long post but I'll do my best to be succinct.

I'm mixing mine with C85, the fuel is Tier 1 91+ E10.
So based on what your saying it's 89 + 10% ethanol.
In my area, 87,89, & 91 all contain 10% ethanol, according
to the pump. So obviously 91 here isn't 89 + 10%.
Looking at my logs I have yet to see any knock.

 

[50BMG]

This will be a long post but I'll do my best to be succinct.

First, there's this misunderstanding out there that ethanol blends are all the same. The reality is, the E10 blend you get with 93 is different than the E10 blend you get with 87. Furthermore, much of the time, the "E85" blends you get are ethanol mixed with trashy 85 octane.

This has impacts on the octane ratings resulting from different mixtures of pump 93. What does that mean? It means that in certain parameters, it's BETTER to mix pure E85 with a higher ratio of pump 93 than it is to mix a lower amount of 93 with a low grade ethanol blend.

As you can see, blending quality 93 with trashy low grade ethanol blends (which have 85 octane as the remainder component) isn't always the best solution.

From the snippet of the chart, the red are eliminated as a reduction in total blended octane. The orange are highlighted as a "not really worth it" section where you're getting a slight octane increase but it's not really worth the brain damage and hassle of mixing your fuel.

The yellow are 94 octane (a slight improvement) but again, not exactly moving the needle. The light green is 95 octane where it starts to really create noticeable benefits worth the exercise. The solid green are 96+ where it's obvious those are meaningful and should be worth the effort.

Now let's examine the "limits" for an untuned system. If we set a 30% octane content as the max we should run without unacceptable fuel trim adjustments, the constraint shaded results with this:

If we eliminate these from the original table (or overlay) the result is this:

Lastly, if we evaluate these preferable areas to try to maximize the amount of octane increase and minimize the amount of total ethanol, we end up with this:

So what does that all mean?

Well, some obvious and not so obvious takeaways:

1) The meat or sweet spot of this is around the 50% quality 93 mixed with E50+ ranging to increased 93 ratio (up to around 80%) mixed with even higher quality Ethanol (up to 85%).

Once we examine how much octane we're getting with each combo compared to how much we're increasing the amount of fuel flow and trim adjustments, we arrive at the area where the best combo of upping knock resistance compared to the increase in ethanol % is around the 70-75% quality pump 93 enhanced with 30-35% of E75-E85.

2) Hitting this from the NEGATIVE side, running a quarter tank of 93 and the rest E30 results in a near unacceptable increase in fuel flow (beyond the 30% ethanol) with little to zero increase in knock rating.

Furthermore, contrary to popular misconception, having 90% of your tank quality 93 and splashing it with anything less than 60% Ethanol isn't really doing much. You're having to mix fuels and getting a very very small increase in knock resistance.

Case in point, 3/4 tank of quality 93 mixed with 1/4 tank of E30 does virtually nothing for knock resistance (from a chemical standpoint).

3) I didn't include any thermal benefits, so yes, increasing ethanol content even if it results in an even or marginal increase in knock resistance could be beneficial due to the reduced combustion chamber temps, but those benefits are more difficult for any of us to quantify and the question would loom whether it's worth the headache of blending or the potential drawbacks of running more Ethanol on an untuned setup.

I get what you are saying, and I personally thank you for the reply!!!
For the record, I never said I was mixing different blends of "regular" E10 fuels.
The only "oddball" mixing I was doing (because I'm a cheap 57Y.O. bastard), was making an @91 octane equivalent fuel for highway use out of mixing 89 octane "E10" gas (which I test for E percentage every time) with E85 fuel (which I also test for E percentage every time). Off the top of my head, mixing 2.8-ish gallons of a tested 90%-95% ethanol E85 (yes, the Speedway gas station near my house HAS tested for 95% ethanol "E85" before!), along with the balance of the 15.5 gal. tank (@12.7 gallons of 89 octane gas, which has consistently tested to be a 6%-7% ethanol content) yields me @ a 91-92octane fuel in the @E20 range of total ethanol content.
The car ran beautifully, even at short blips on the highway in the 100+ range

When I'm not going on a "road trip", the E30 mixing I was doing to boost octane and hopefully performance was supposedly yielding this, as I previously posted above:

In Sport mode, the car runs very well on the E30 Mix from my local pump (11.1gal. 93 octane gas @6%E + 4.4gal. E85 @90%E=@ 96.4 Octane mix).

So these octane results also follow what you wrote, I think??? (my E30 mix is comprised of @28% of what tests to be E90 fuel)
So, from my admitted "non-fuel-pro" guy perspective, it seems to be worth the effort to get a 96-97 octane number (which yields me a better ignition advance & resulting horsepower), SO LONG AS I am not incurring any engine damage from burning a higher/E30 level of fuel instead of the Ford suggested "max" of E15 fuel that the ECU was evidently factory programmed to compensate for....... No?
I understand I'm leaving some horsepower on the table running a high octane E30 without a better E-tune, but I want to get a better tune as well. I just need some more direction as to how to get it done.

I'm an old school carburetor guy. I can just about tune a Holley with my eyes closed.
I need to learn more of the details of how this EFI/ECU shit works! LoL...

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