Older vehicles, ethanol blended gas

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Rick Courtright

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Hi,

This will take a while:

I try to learn something new every day, but even so, sometimes I find a tidbit that really opens my eyes. Recently, one of those moments came while replacing spark plugs in the "primitive" '88 Toyota pickup that lives here. Plain Jane, 4 banger, 2 bbl carb, "sorta" electronic ignition (no points, but timing's still adjustable by hand ) and about as far from being a powerhouse as they come.

This "new knowledge" came about while trying to figure out why the truck fouled a plug on a recent trip across the SoCal and AZ deserts to Tucson. Normally, it loves that run, because we can scare all the spiders out of the exhaust on both sides of the river, and it loves AZ gas once we get on their side. The stuff's near magic compared to CA's own proprietary "clean air" blends. In fact, a year ago, I made that trip just before going in for the biennial smog check. And that "terrible dirty smog producing" gas was what was still in the tank when I went for the test. Result: the numbers generated (O2, CO2, CO, HC and NOX) were better than with CA gas. In fact, that test was the cleanest I'd had in the dozen plus years I've been driving this truck.

But that doesn't explain my fouled plug. It had completely bridged the gap between the center electrode and the side electrode. Center insulator was relatively clean as were the other surfaces which normally collect deposits. It was almost like some piece of crud went flying around in there, got stuck between the electrodes and welded the gap closed. Though rare, fouled plugs aren't unknown to me, but this one had me baffled. It only had about 10k miles of a normal 25k mile service life.

Since I use their plugs, I went to the NGK website. They didn't tell me how my plug got fouled, but told me things about how ethanol gas affects the "performance" of spark plugs They describe ethanol as being "hard to ignite." In terms a reloader would understand, it's like like loading a cartridge with slow burning powder. In order to get good ignition, we often have to use a "hotter" primer. Hotter here can mean either a more vigorous flame, a longer duration of the flame, or a combo of the two. "Brisance" is the technical term, but hotter or not so hot work for most of us..

So with a conventional ignition system, NGK advocated advancing the timing, a little bit at a time, from the factory setting, first to the point of getting a smooth idle, then a little further until "pinging" is noticed, and back down a degree or two from there. All adjustments should be made in increments as close to 1 deg apart as possible to make fine tuning practical. They went on to say "modern" engine management and timing systems take care of this "change" on the fly, but the older systems don't offer that luxury, hence manual changes are required.

The rationale is that the burn gets started and spreads like always (like our powder burning down the barrel), but it gets to burn longer before the optimum point in the engine's rotation. It doesn't help increase the BTUs in the ethanol, but allows us to get the most out of those it has.

Ok, the normal timing at idle for this vehicle is 0 deg--no advance, no retard. With the engine revved up, it probably advances to about 28 deg BTDC (before top dead center.) Advancing the idle timing "effectively" spreads out the built in advance and produces a better burn. Simple concept!

So I got to playing. When the vehicle goes in for its next smog check, they'll do a "visual" test which will determine if the timing's at the factory spec of 0 deg, so I'll have to set it back, but currently, I'm up to about 2 1/2-3 deg BTDC and Gavin hasn't come to put me in "Climate Change State Prison." So far, the idle's improved, the cold start performance is better (ethanol doesn't like freezing or below for sure, and doesn't seem too happy even at 40-45 in my truck) and the "around town" mileage has picked up about i mpg. That doesn't seem like much, but it's about 5%, which the engineers will spend billions on trying to achieve. I haven't gotten a chance to get a couple of full freeway tanks thru it since this change, but expect some improvement there, too. I suspect a 10% to 15% increase in freeway mileage wouldn't be out of the question.

So... if you drive a "relic" like I do, you've noticed a serious drop off in mileage with a corresponding loss of "feel" from the engine with ethanol blended fuel, and you don't mind twisting a wrench, you might try NGK's suggestion. As for the other problems with ethanol gas, especially with small engines, we're still on our own.

But what if you drive a newer car with that stuff in it? Well, there you've gotta trust the guys who designed and programmed "the brain" (computer) on your car. Between purely electronic ignition, together with such things as VVT (variable valve timing) engines, you're at their mercy. However, considering the power they're getting out of smaller and smaller engines, I think they've done at least some of their homework. So the chemistry of ethanol will reduce your fuel economy no matter what, but the physical running of the engine that allows manual timing adjustment may get far better. And if you try NGK's advice, please let us know how it works for you!

Rick C
 

32shooter

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I run ethanol free gas in all my small engines, may not be available in California though. Some day I will try it in my 1999 Wrangler to see if there is any noticeable difference in performance. Costs about $1 more a gallon.
 

Dan in MI

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Rick, yes, by advancing timing you will get the benefits described, BUT, (big but for a CA resident) it will raise your NOx. And possibly other constituents. Remember all of your timing and fueling is balanced to maximize mpg while still meeting emissions requirements. CARB is toughest, as I suspect you know.
 

Bear Paw Jack

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32shooter said:
I run ethanol free gas in all my small engines, may not be available in California though. Some day I will try it in my 1999 Wrangler to see if there is any noticeable difference in performance. Costs about $1 more a gallon.

Locally Non-ethanol gas is quite competitive, usually within $.05/gal. Problem is it varies widely and is not available everywhere. Where I live it's with in 3-5 miles. I've noticed better mileage on highway trips. But the next time you fill up, it may be back to blended.
 
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Unfortunately, there’s no station selling ethanol-free unleaded within 60 miles of us. And we live at the edge of a large petroleum producing area.

I’d sure like to buy ethanol-free for my chain saws and lawn mower.
 

Rick Courtright

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Dan in MI said:
Rick, yes, by advancing timing you will get the benefits described, BUT, (big but for a CA resident) it will raise your NOx. And possibly other constituents. Remember all of your timing and fueling is balanced to maximize mpg while still meeting emissions requirements. CARB is toughest, as I suspect you know.

Hi,

I understand just enough about the interactions between settings and the result in emissions to be dangerous, Dan. But I figure the NGK guys might know a bit, since they have to build components which comply with the latest regs. One thing they talk about with the older engines is remind us the "standards" were set up with the fuels available when the vehicles were made, so my specs are now 30 yrs old.

Sometime a few years ago, probably about the time MTBE was phased out of "CA gas" to be replaced by ethanol, the State revised some of the limits on older vehicles. They tightened them up. I'm kind of assuming they were trying to keep current with fuel changes, though most everybody agrees a huge part of this smog testing stuff is nothing but a moneymaker, and if the air gets cleaner, that's a side benefit.

My smog guy's pretty good about diagnosing problems from looking at the printouts. He's also given me some tips regarding the teeter totter relationship between some of the exhaust components, such as a decrease in HC is quite likely to cause a measurable increase in NOx in many engines (kinda what Dan said, no?) In looking at my numbers over the years, it seems everything on this truck seems to go up or down in sync. I've no idea why, but all of the numbers are currently way below the max standards as well as the average numbers from the same vehicle around the State. So I suppose I have a little wiggle room where I can improve the engine's performance/driveability and still stay "in spec."

But as you said, CARB is a huge PITA, and the "visual" (where they'll check the actual timing, so I've gotta reset it to factory for the test) gets a lot of people. Especially those who modify their engines: a number of mods may not harm (and possibly even help in some cases) tailpipe emissions, but they're illegal to install unless the mfr has paid the mordida and gotten a CARB exemption notice, which translates into an under hood sticker the owner has to put on or else fail the visual.

It's all a big racket as far as most of us are concerned. And it's getting worse--they've decided most new cars will go at least five years with no noticeable change in emissions from the factory specs, so one doesn't have to go thru the biennial inspection until about year six. Good idea? Well, they sold it as one, but a sharp pencil exposes the lie on paper. My vehicles all have to go thru the biennial testing. The cost at my guy's shop is $55, of which about $10 goes to Sacramento. So three tests, six years, gets them about $30. But if I buy a new car, I have to pay an extra fee for the privilege of no smog test until about year six. It's about $20/yr in most counties. So my new car will go five years (5 x $20 is still $100, isn't it?) then get tested in year six, which sends another $10 their way.

So my old vehicle nets them (Sacramento) $30 over six years, while a brand new one sends up to $110 to their coffers. But, they argue, the old system will cost me, the motorist $165 over six years, the new one $155, meaning I save about $10 over that six year period with a new car by not having the actual tests so I should be thrilled. Whoopee! Now tell me this is all about clean air? Might as well tell us it's for the chilluns, no? ;)

Rick C
 

Dan in MI

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You're 1/2 right about the guys at NGK. They build a component but aren't responsible for emissions. I was hoping not to have to type all this, but I knew I would. You are right about the gov't scam for $$$. Today's cars are so clean we often wondered if it was even possible to kill yourself with car exhaust in a closed garage anymore. And it has been shown newer cars help CLEAN the air in very dirty cities (none in the U.S.)

Emissions production/reduction is a complicated thing. Raise one constituent and you lower another. Your catalyst basically stores oxygen. Your engine is designed to run just a tiny bit rich and then lean, back and forth over and over and over. What that does is either add or remove oxygen from the cat. Once the cat "lights off" (gets above ~700*F) it can make the conversions required. You run lean a for a couple seconds and the cat stores up oxygen. Then as the engine goes rich and the stored oxygen is atoms are added to CO and HC (hydrocarbons) to make CO2 and H2O. Then it switches lean again to collect NOx (NO2, 3, 4, 5) The cat grabs the extra Ox and lets the nitrogen pass through. Then the cycle repeats. The cat can only store so much so running lean too long (hot) creates more NOx than can be stored for conversion.

The majority of emissions are created in the first 30 seconds after start up on the EPA/CARB test. The cat is cold and it takes ~20 seconds to light off. Once lit off it does a great job, but there are conditions where it taxes the system. Hard accelerations being one. Then you have to add in the evaporative system (catches fuel vapors from the tank) every so often those have to be added to the fuel stream to be burned (once again the system can only store so much) This is done as a best estimate of how much vapor is available to burn. It is added to the fuel calculation and then the O2 sensors tell us how well we estimated and the adjustments are made. All of this is done thousands of times a second. This can be done down to each individual cylinder firing. 3000 rpm x 8 cylinders = 32,000 times a minute. Your engines controller is busting its butt. Remember it does a lot more than just fuel/air and timing.

That's enough typing for now.
 

powder smoke

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In these parts most gas stations have ethanol free fuel real gas! 'bout 20
cents more per gallon. my Pick is a diesel so the only fuel I buy is the
ethanol free! for my chainsaw mowers weed wacker etc. Lindas blazer get
the ethanol formulated gasoline except when I use it. She's a penny pincher.ps
 

Mobuck

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When ethanol first went into gas, we were using several gas fueled tractors. I spent hundreds of $$ on the "lead substitute" but now I'm skeptical of it's worth. We don't pull those old engines as hard as we used to and haven't used the lead substitute for several years w/o any issues with valves or performance. For a "beat around" vehicle, I'd just drive it and nt be concerned about future issues.
As for the "smog checks", I won't say how I feel about such stupidity.
 

Jimbo357mag

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We used to have vehicle inspections and smog tests in Florida. There were many tricks to get an older car through the inspection process but all that went away when several politicians had their cars stuck in inspection lines for hours and they decided to remove those laws from the books. No more inspections at all.
 

Paul B

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"They tightened them up. I'm kind of assuming they were trying to keep current with fuel changes, though most everybody agrees a huge part of this smog testing stuff is nothing but a moneymaker, and if the air gets cleaner, that's a side benefit."

For years I ran a 79 Ford F150 4x4 straight pipe. No muffler and no catalytic converter. Running leaded regular gas to boot while it lasted that that truck passed emissions every time. Then the state went chicken dung and there had best be a fuel restrictor and catalytic converter on the vehicle or else. So I have to buy a replacement fuel restrictor and climb under the truck the replace the converter. Good thing I didn't throw it away with the restrictor. Biggest problem after that was I had a 40 gallon tank in the bed of the truck and the opening was too large for a restrictor to fit so I jury rigged one to pass. Guess what, epoxy and unleaded gas fumes don't mix and when they checked my jury rig was as loose as a goose so my truck didn't pass. I loved that truck. It sounded like a B29 running up when I hit the foot feed hard. That thing would go anywhere. Interesting thing is with even unleaded gad with the catalytic convertor that truck would do an honest 19 MPG. The convertor knocked that back to 17.5 on average.
Paul B.
Paul B.
 

RSIno1

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wheelgun1958 said:
I thought the 25 year cutoff for smog test was federal.
1975 and older for CA. There has been talk of raising it but they love getting an extra few $$$ for each car. It doesn't mean you can pull the smog equipment off it just means they aren't checking. Depending on how mad you make the cop that pulled you over for doing a burn out from the local cars & coffee he can cite you for missing/modified emission and then you have to put it back to stock.

Ethanol has about 1/2 the energy as gasoline. Burns at a lower temp so doesn't get hot enough to burn everything. If you have even a slight amount of oil getting past the rings or valve guides you'll be fouling plugs.
See if Accell or Mallory offers higher voltage coils for your car that will help. I put them in my 300,000 mile Ford Excursion and it quit throwing misfire on startup codes.

If you can get real gas for 20 cents a gallon more it's probably cheaper on a per mile basis than using the ethanol laced stuff. Check your mileage using a couple tankfuls of each. Ethanol generally gets 8-12% less mileage.
 

gunzo

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Rick, There are a lot of articles & tons of photos about reading spark plugs. Colors, flash, etc. can indicate need for a change, & what to change.
I just took a quick look to help jump start my memory & quickly found a downside as ethanol cleans plugs in a way that makes them hard to read. But if you want to overload with info on the subject, just google; reading spark plugs.
 

gunzo

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Dan in ,

Wouldn't increasing percentages of ethanol require a heat range change with the plugs, as well as altered timing?

I was taking a crash course on changing from gasoline to straight alcohol about the time I quit racing & that was years ago so only bits of info remain.
 

Bull Barrel

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Using straight alk you must jet almost 3x richer and raise compression significantly. Yep, sparky things and timing adjusted. On cool nights you need to block the radiator to keep heat in the engine.
Then you have to drain the oil every night because with the richer jetting the cylinder walls get washed with fuel and it gets past the rings into the oil. Some oils tolerate this and some don't. Either way more and more alk is lubricating the engine.
Plus, much ethanol is sold "wet" aka it has water in it as the stuff attracts water.
On circle track engines some folks change the firing order by swapping the #5 and 7 cylinders. Makes for a smoother torque curve.
 

Dan in MI

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Straight alcohol yes, but E10,15,20 not so much. Especially with newer engines. As far back as 2007 we could take an E0 car (pure gasoline) and just change the calculated AFR (air fuel ratio) and it would run just fine on E-22 (Brazil fuel) The computer and emission system would take care of the differences. It would take some crank/start up fueling work to start under 50*F reliably but once started, running was no issue at all. (Brazil only needs to be able to start down to 30*F) Cold markets with E-20 are a whole 'nuther ball o' wax for starting fuel.
 

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