Maybe E-10 is better? - PentaStar (Flex Fuel)

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So since I got the Caravan I have been using ethanol free Petro Canada gasoline 91 octane because I'm not paying for it and why not benefit from the added detergents in their premium gasoline over the regular (as they claim there is). Either way it's Top-Tier so it isn't really necessary and I certainly don't need 91 octane but heck it's free so why not.

Well I didn't connect the issue until I was thinking about it on the drive home one night a few weeks back.

There was an ever so slight stumble here/there when hot-restarting for the first minute or so. I thought it was odd and most likely a coil breaking down slightly or a plug due to the heat soak because this is the only time it would occur.

2 Weekends ago I took the plenum off because it was bugging me (I know it's a new vehicle), and I took all the plugs out and gapped them to 0.44 as required as they were set between 0.30-0.35 from the factory. (Stupid FCA engine plant). Anyway. I put it together temporarily and scoped the ignition coils and and they all looked perfect on hot-restart when it had the slight stumble which I thought was really odd and thought ok, I need to look elsewhere.

I put the van back together fully and needed gas, as I pulled up to the pump I had a thought, what if it's the premium gasoline having 0 ethanol (This is a flex fuel vehicle), or what if its the 91 octane (hard to believe), or maybe a combination of the two with the winter gas formulation. And started thinking further that this annoyance (not really a problem) started shortly after I started using the ethanol free formula.

Ok so I had a quarter of a tank of Ethanol free fuel when I gassed up. I filled it with E-10 and then kept topping it off each night I would get home with E-10. And sure enough the stumble disappeared. Not believing this I then refueled with ethanol free and it started with the slight stumble again although not as much because the tank still had some ethanol in it. I again played with ethanol and non-ethanol fills and every time I go back to E-10 the issue goes away.

I burn a lot of gas each week so the results are quick to happen.
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When I had the plugs out for gapping the colour was a nice tan brown colour so I know the burn is proper.

It's really weird, but it makes sense as my dad's 2012 that I drove before he had it only saw regular E-10 gas with the fleet card and it never stumbled. Even to this day with 300K on the clock it's smooth as butter. The in-laws as well and I know he uses Petro Canada exclusively for the points and always E-10 as it's about $0.10/L more where he lives compared to here.

Just thought I would share here in case anyone else experiences the same thing. I am going to try the premium again when the summer gas returns to see if it's just the combination with the "winter blend" they are using that is causing the issue.

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The gap grows over time so the shorter gap was probably to compensate for that.
 
Originally Posted by dishdude
The gap grows over time so the shorter gap was probably to compensate for that.

Their book-spec is 0.44 though so I assume that is what it should have been, or the book-spec is printed wrong?
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Originally Posted by MrMoody
Ethanol would clear any moisture that might have gotten into the system ...


I guess Summer will tell.
 
I don't think it's the E-Zero fuel. I think it's the 91 octane. Your engine is designed and tuned for 87 octane fuel. The higher octane rated fuel is not needed so it might not be exploding correctly, per say, versus the 87 octane fuel. Both of my 3.6 engine vehicles run perfect on 87 anything. I run only what the engine was designed to run on.
 
So much junk science in this thread.
Octane doesn't make the "explosion" not run correctly.
It's not the water, unless StevieC somehow managed to get water into his first tank of E0, enough to overcome the residual ethanol...but then it should be in the bottom of the tank, not in the injectors....that's where the water goes when there's no co-solvent.

Can't explain StevieC's observation, but the above two ain't it !!
 
Originally Posted by oldhp
I don't think it's the E-Zero fuel. I think it's the 91 octane. Your engine is designed and tuned for 87 octane fuel. The higher octane rated fuel is not needed so it might not be exploding correctly, per say, versus the 87 octane fuel. Both of my 3.6 engine vehicles run perfect on 87 anything. I run only what the engine was designed to run on.

I second this. The way to find out for sure is to run several tanks of (in any order) 91 E-0, 91 E-10, and 87 E-10. This will paint a better picture and determine if it's an octane or ethanol issue. My money is octane.

Either way, use whatever it runs better on. If you're saying some other entity is paying for it, use what the car likes. If you're saying there is no price difference between 87 E-10 and 91 E-0 (I doubt it), again, use what the car likes.
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OK, can someone link me to something about octane disrupting the "explosion" and causing a stumble ?
 
Originally Posted by Shannow
OK, can someone link me to something about octane disrupting the "explosion" and causing a stumble ?
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Okay I don't agree with that part, but I have heard cases where higher octane than needed caused minor issues like StevieC describes.

Edit: I might be able to find some info on espresso shots disrupting your bowels, therefore causing an explosion and making you fall over from the fumes.
 
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I don't get it. Your car is designed for 87 gas. You used 87 and 91 and found that 87 works better. What is the problem you are trying to solve now?
 
Originally Posted by Shannow
OK, can someone link me to something about octane disrupting the "explosion" and causing a stumble ?


I remember reading theory about that in the late 1990s. Essentially how running higher octane fuels when timing wasnt set for them could change combustion dynamics and complete burn. As I recall, it was also noted in relation to H2S odors from catalytic converters. No specific links, just recollection.

But since the late 90s, Id suspect that sensors and variable timing has made much of that further moot...
 
I once had a 60hp Johnson 3 cylinder (3 carb) 2 stroke outboard. I was running 93 octane Shell gas in it all the time and it one day went into limp mode. I took it to a very experienced OMC (Johnson/Evinrude) mechanic. I never told him anything about the gas I was running because I didn't think it had anything to do with the issue.

He checked it and called me and asked if I was running high octane fuel. I told him yes, and he said to stop doing that and just run 87. I can't remember exactly the explanation, but he said it was designed to run optimally on 87 and that the 93 was causing, again IIRC, upper cylinder temps to be to higher than desired, triggering the limp home mode. I started running 87 and the problem never occurred again. He did nothing to the engine except run diagnostics. He didn't even adjust the carbs because he said they were just right.

This has been 25 years, so I may be missing something or messing something up in the explanation, but that's what I remember.

Anyway, back on topic....How can OP be sure there is actually 10% ethanol in that E10 fuel? I saw a car mag or website article awhile back where they tested pump fuel in the US (I can't remember where it was other than it wasn't a big corn state) and the E10 actually had more like 1 to 2 percent ethanol in it. I'm guessing the blender or refinery probably cut back due to gasoline being less expensive. Anyway, I wouldn't assume the ethanol content to be what is advertised, unless the Canadian laws are pretty strict about ethanol content.

The one sure thing is that OP observed a benefit from the 87 E10 labeled fuel, so the answer is to just run what works. My 2018 Pentastar runs just as well on E10 87 as it does on ethanol free 91 octane, so I just run the cheaper gas from a reputable brand. However, my 08 3.8 runs noticeably stronger and better with the ethanol free 91. I run the 87 for a few thousand miles until I get some light pinging. Then I'll put a tank of ethanol free 91 in there and do a couple Italian tune-ups, and it cures it. Then it is back to 87 for a few thousand more miles. It is just a matter of finding what your engine likes through experience.
 
Baffling! I've tried several different fuels in my Escape 2.0T and it just plain runs better on Ethanol Free gas. It doesn't matter if it's 87 E0 or 93 E0.
 
Originally Posted by StevieC
Originally Posted by dishdude
The gap grows over time so the shorter gap was probably to compensate for that.

Their book-spec is 0.44 though so I assume that is what it should have been, or the book-spec is printed wrong?
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Check several references .
 
Originally Posted by StevieC
Originally Posted by dishdude
The gap grows over time so the shorter gap was probably to compensate for that.

Their book-spec is 0.44 though so I assume that is what it should have been, or the book-spec is printed wrong?
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Check several references .

In our state , unless it is specifically labeled zero ethanol at the pump , all gas may contain up to 10% ethanol .

Both of our cars ( all GM vehicles ) get better MPG with premium gas , which I assume has up to 10% ethanol . Can not tell any difference in the way they run .

Have not run enough E0 in them to tell how that runs , due to the additional cost per gallon .

I have switched to E0 for the mower & weed eater string trimmer .
 
I was told very recently that Petro Canada at least in the past (not confirmed if it's still true) used methanol in their premium winter blend instead of ethanol. Apparently methanol is even more corrosive than ethanol (but that's a different topic). If you're stuck using Petro Canada then you may have a choice of either ethanol or methanol.

Finding this out I'm now sticking to esso or shell 91 octane both of which are free of ethanol and top tier gas. I was running regular until my Caprice developed a ping under light load since I hooked up the heat riser valve for winter cold starts. Time will tell if that solves my problem.

I recall years ago working at the ford dealership at the start of winter we would have several people come in with a rough running on startup complaint that the techs attributed to the winter gas switchover. I can't confirm whether that was the problem or not but it's worth thinking about.

With the knowledge that there might be methanol used in Petro Canada winter high test I would stick with their regular.
 
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Originally Posted by WyrTwister
Originally Posted by StevieC
Originally Posted by dishdude
The gap grows over time so the shorter gap was probably to compensate for that.

Their book-spec is 0.44 though so I assume that is what it should have been, or the book-spec is printed wrong?
21.gif



Check several references .

In our state , unless it is specifically labeled zero ethanol at the pump , all gas may contain up to 10% ethanol .

Both of our cars ( all GM vehicles ) get better MPG with premium gas , which I assume has up to 10% ethanol . Can not tell any difference in the way they run .

Have not run enough E0 in them to tell how that runs , due to the additional cost per gallon .

I have switched to E0 for the mower & weed eater string trimmer .


In Canada most premium fuel is free of Ethanol with very few exceptions. Some pumps are labelled to show this and some don't say at all. Some don't specify regular or premium but just say may contain up to 10% ethanol.
 
I'm going to try 91 octane at Esso (Exxon) for a couple tanks and see if it stumbles. I'm more inclined to think it's the Methanol in the Petro Canada premium doing it. We were already on Winter Gas here when I bought the van in October.

As for plug gapping I have checked other sources. It's all 0.44 with the exception of Autolite plugs on Rock Auto calling for 0.40 for some reason.
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