Gasoline contains ethanol. Ethanol absorbs water. You'd think that would be a good thing that helps remove condensation that happens in the gas tank. BUT Water gets absorbed naturally along the distribution channel. AND If you were a refiner, transporter, distributor of gasoline, wouldn't you like to sell as much water as possible at $4/gallon? Would be very simple to load up as much water as it would take. SO When I go to the pump, how much water am I buying?
And the question that started all this: For an infrequently used vehicle, should I be doing something else to keep the fuel system from rusting?
mike wrote in news:jac2hn$kki$ snipped-for-privacy@dont-email.me:
It doesn't, actually. The distribution channel is specifically designed to /prevent/ that.
But they don't do that. Water corrodes their equipment, so they try like hell to keep it out of their pipes and tanks. Ethanol was forced by law on the gasoline companies; they hate it, specifically because of the special (and costly) handling and distribution it requires in order to minimize corrosion.
Corrosion is caused by oxygen. Gasoline does not contain oxygen, but ethanol does. So ethanol is added to gas at the last possible moment, just before the gas is shipped to the retail stations.
Ethanol also causes gasoline to oxidize (spoil) fairly quickly. That's why gas companies never store gas/ethanol blends anywhere but in retail station tanks, where they are reasonably assured of a quick sell-through before they risk spoilage.
Almost none. Or none at all.
Ethanol is mixed into gasoline at the distribution center, which is where the truck is filled before it makes its rounds of the retail stations it services. Ethanol is stored in its own tanks at the DC, and, like the gas, it's not ever stored long enough to suck up much water. This is by intent and design, not by accident.
Most gas stations have their tanks filled at least once a day. Any water that might be in the underground tanks is temporarily stirred up by the filling-action and ends up in somebodys' vehicles' tanks. This minimizes any water buildup in the tanks.
Most water in retail stations' underground tanks enters through the holes in the pavement (those round, painted metal covers you see) through which the tanks are filled each day. And even then, that happens only when the truck driver pulls the covers to fill the tanks.
Sta-Bil. Google it. With that spelling. It's sold everywhere.
Make sure you get the Ethanol Compatible Sta-Bil. There is still some of the old stock out there that doesn't work as well with Ethanol in the mix.
Another thing is don't buy large quantities of gas "just to have it on hand" unless you have a GOOD well sealed storage unit. Most gas cans out there don't fit this category. I also try to rotate stock once a month at the outside, this includes pre-mixed stuff for weed-eaters/saws.
it's not a lot, but it's definitely there. pour some fresh ethanol blended gasoline into a brandy glass and swirl it around like you would for brandy. as the ethanol evaporates, you'll see droplets of water start to precipitate around the glass walls.
as to how much is in there, i don't know off hand, but i think it's possible to dissolve 1% or so. not a lot, but 3 cents per gallon multiplied by the millions of gallons sold per day, each day of the year
- that'll buy a whole lot of lobbying power.
how old is the vehicle? many vehicles use hdpe tanks, and have done so for more than a decade. the rest of the system is designed with the ethanol/water equation in mind.
not the water that's added at the refinery. once saturated, you don't want /more/ water getting in since that precipitates - as someone else posted a while back, it's called "phase separation".
b.s. it's all highly corrosion resistant. it's had to be since ethanol came on the scene.
b.s. they love it. not only do they get tax benefits, they get to sell more gallons of gasoline because the calorie content is lower.
that's small beer compared with the additional revenue. up to 5% additional revenue.
tegger, you're wrong on that. oxygen is a gas. it dissolves in liquids. not much, but a bit. then we get tot he oxygen content of the multitude of chemicals /in/ gasoline...
/everything/ is added at "the last possible moment". the tanker pulls into the loading bay, the additives and chemical/ethanol/detergent/whatever packages for the destination brand are added, and the base fuel goes in last to mix it all up.
define "spoil" and define "quickly". [hint: oxidation is not the primary problem with storage.]
no. refineries don't "store" blended gasoline because they don't need or want to have money tied up in inventory when they can deliver "just in time".
again, that's a financial decision, not a spoilage decision. blended gasoline /is/ regularly stored when it's getting shipped in bulk as part of the commodities trade. for instance, oil tankers don't just ship oil, they ship all kinds of refinery products. diesel, gasoline, kerosene, even benzene and many many other derivatives, all get stored and shipped in /huge/ quantities if it's part of that trade.
not true. do the brandy glass experiment.
did you intend to say the water that's in there is by design, not accident? if you did, you'd be correct.
there is a /little/ moisture absorption from air, but it's minimal, especially since all the storage facilities are sealed to prevent evaporation.
a little chemistry and a little understanding of the commodities markets, and you might be able to sound like you know what you're talking about. but you haven't so you don't. and i /do/ wish you wouldn't make shit up about stuff you don't know.
I drive it under 2K miles a year, not at all in the summer. Got 100K miles on it. Passes all the EPA emissions tests.
Symptom is that it stutters on acceleration...sometimes...infrequently. Like it misses a beat. It' not a serious problem, but I don't want it to quit on me at an inopportune moment. Has a very old ECU. Reads out the "everything's OK" code, but the diagnostic ability is limited.
I pulled the fuel line off the injector assembly...has plenty of fuel flow so the filter isn't clogged and no indication of anything like water coming out of it.
It might be related to where I buy gas, but don't have very many samples. That got me thinking about water in the gas, which led to the ethanol question. IF I could run it dry and fill it up with fresh gas, would that absorb water in the system? Not if the "fresh" gas is already saturated...
I did start putting Sta-Bil in the motorcycle and the generator last year. Haven't tried it in the truck...was worried about whether it was compatible with emissions sensors. Shoulda read the label, says it is compatible. I'll try it in a couple of months when I run the tank down.
i'd look into things like the ignition system and egr if it has one.
ignition systems can be hard to diagnose sometimes - surface spark tracking inside a distributor cap from salty fingerprints and sparking erosion inside loose spark plug end cap screw terminals are some of my favorites. the latter particularly...
blocked egr passages give the "miss a beat" symptom, but it's more of an acceleration "flat spot" than stutter.
I pulled the distributor cap and made sure it was clean inside. I should pull the plugs and also check the wires. I did a lot of googling and most of the recommendations were for fuel problem instead of spark. Would be a lot easier if I could produce the symptom on demand.
frankly, unless the vehicle is parked somewhere where water can actually run into the tank, the amount of water we're talking about here won't be a problem. especially not when the engine is hot.
for sure.
the reason i say spark is because i spent ages chasing an intermittent like this down one time. checked, cleaned and replaced almost everything, but it still kept on happening. even a short while after changing spark plugs. finally, i noticed that on the type of denso spark plugs i was using, the screw-on terminal caps were working loose. i hadn't tightened them as i normally would since they'd been crimped and i assumed they'd stay tight. but that wasn't the case.
when i took a cap off, it was black and eroded inside from sparking! when i checked the others, they were all like that. i'd kept the old set for some reason, and they were like it too. after cleaning the new ones up and putting them back in with tight caps, the problem went away. but after finally diagnosing the problem, i changed them out again anyway and use only one-piece ngk's now. i've never had that problem recur.
use gloves when cleaning spark rotors, caps and spark plug insulators. seriously, finger sweat can cause condensation and spark tracking. if you have an aftermarket distributor cap, make sure the terminals are aluminum, not brass. copper oxide from the brass can be a conductor if debris is inside the cap.
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