I'm curious about fuel stabilizers.

Q's:
How do they work?
Do they reduce available power?
Why don't the fuel companies add it?

Any chemist out there?

 

Fuel stabilizers work, but they have to be mixed with fresh fuel. Can't wait 10 months and decide, hey, maybe it's time to add some to the tank. The refiners don't use it because it costs more money, I'd expect. In open or vented fuel systems commonly found in vintage or collector cars and trucks the ethanol laced fuels tend to absorb moisture and cause phase separation in the fuel and attacks alloy castings in carburetors.

So it's a situation where ethanol laced fuel isn't going to cause problems necessarily in running, but it isn't a good choice for cars that sit for many months. When the temperature and humidity is just right can see condensation dripping on all the metal parts including the fuel tank. The exact same thing is going on inside the fuel tank as well, humid air is drawn in a partially full tank at night and fuel vapors and "light ends" released during the day.

This is one reason fuel systems are completely sealed, to reduce emissions. Small amounts of water or moisture are absorbed by ethanol. But keep in mind the fuel stabilizers or preservatives have nothing to do with ethanol, this is a separate issue that just makes the situation worse, pure gasoline will also start to stale or varnish eventually. Better to just drive it! Keep fresh fuel in the tank, and topped off.

 

Unfortunately for me ethanol is all that's available and I'm not getting many miles on the truck so I've started to fill short so less gas sits around (36 gal tank)

 

Ethanol gets blamed for everything from carburator problems to tornados and bad movies. the fact is we had carburator problems before ethanol was blended into gasoline, I know this for a fact because I was there.

I own a farm/ranch in eastern Oregon and we have pivots and wheel lines these wheel lines are started and moved twice a day with air cooled gas engines that have water raining down around them 24 hours a day for months on end. then they sit all winter untouched. they have a hood, bucket something over them to stop the direct irrigation but they live in a rain forest basically. I have been keeping a couple dozen of these things running for about 45 years now and I remember the EXACT SAME AMOUNT of trouble pre ethanol as I experience today. so if this isn't a test you tell me what is.


The stabilizers help some for storage. they don't hurt anything and they're not added to fuel at the station because of cost. as far as performance if you want better gas buy better gas there isn't any substitute. if you're really into it get an octane tester, you'll be disappointed in most of the fuel you buy even the non-ethanol premium. this is why in my high compression engines I run a blend of regular and 100LL .

 

I don't have any preignigtion problems since I went with Snow Performance water/meth injection and premium fuel. The alcohol in the fuel will actually increase octane. It's a cheap way to do it. It will also lower the available power as it takes more of it to make the same level. I was told by the local BMW dealer that they tested local fuels and some of the cheaper ones had as much as 20% alcohol. Wrecks havok with injectors and sensors.

In 440's example I believe the culprit is just water.


Lord save us from the goverment!

 

As far as how they work or at least what it is, I think it was here at FTE somebody asked about that. One poster claimed they were a truck driver that delivered to the STA-BIL factory. He wouldn't say what it was, only that it's "food grade" product, and that you've probably heard of it.

 

alcohol is very hygroscopic, meaning it can adsorb water from air, add it to fuel that already has "shelf life" and you are just compounding problems. The longer it sits the mor water ya get. I have worked a second job at a small engine shop for the last 10 years and i agree with 440sixpack gas going bad has always been a problem we sell used mowers and even if treaded 1/2 that are stored over the winter need at least the carb drained to run. But the last 5 years the carbs the sit for over a year and a half or 2 years seem to be full of jelly they doesnt resemble or even smell like gas or the varnish it used to. stabilizer does seem to help but not a cure. I also dont know if its how power equiptment is stored that makes it worse, either outside or in uninsulated sheds that freeze all winter, then spike hot and cold all summer help with condensation as well i think.

 

I use dieselkleen centane booster every tank and have been for years. I'm not sure if it's problematic, but if I forget to use it, I know within a few miles, I develop misses. If I add some, the misses go away almost instantly.

 

Have you seen this? Ethanol free gas stations in AZ. https://www.pure-gas.org/index.jsp?stateprov=AZ

 

I quit using Stabil about 10 years ago after realizing equipment I didn't put it in had no adverse effects. No difference in maintenance between what I used it in and what I didn't. This is mostly equipment that sits for 6-8 months at various times of year and sometimes up to a year. Snowplow equipment sits all spring, summer, and fall, and mowers, bikes, old cars, etc sit from Nov through April or May. I run carbs dry on all smaller gas engines that have a shutoff valve from tank as they are less tolerant. I just haven't had any issues that justify Stabil. On the other hand I saw first hand a friend that used Stabil in his prized antique motorcycle and ended up with a real mess inside the carb come spring.

 

I use StaBil in my mower gas. probably uselessly because my gas rarely sits more than a few months. We do get temperature swings, though, so in-tank condensation is more of a possible issue. So I use it in gas which is turned relatively frequently, and not at all in my truck which may go two or three weeks between starting.... obviously logic ain't my friend.

I suspect the reason manufacturers don't include similar additives in standard gas is simple: probably 99.99% of drivers actually drive their car, and probably fill it at least monthly. Why add the extra cost if no one needs it?

 

If you are going to use a fuel stabilizer then it needs to be a proven quality product. Stabil is not the product as it offers no real protection against ethanol or corrosion. If you want fuel to last 12+ months and have no corrosion then use BC Fuels Ethanol Shield. If you're looking for up to 2 years then you can use StarTron. Both of these products prevent phase separation and inhibit corrosion. Neither are cheap but they are effective especially if you are protecting expensive equipment or bulk fuel.

 

I believe fuel stabilizers help the wide range of "stuff" in gas be more compatible. When I was a kid, dad never used stabilizer and never had problems. Now, I can bank on fuel crapping out and/or separating and causing problems in anything with a carburetor....from little ***** of gel in the bowl to filling the bowl with jelly. No amount of running will dissolve the gel so it's tear down, clean, and re-assemble time. I doubt stabilizer makes more power vs plain fresh gas but by keeping the gas in better shape I am convinced they help engines make the power they're designed to make.

An ounce of seafoam per gallon seems to stop the gelling. I use it in every gallon that my snow blower, push mower and riding mower sees. I run my old truck enough that I only seafoam it in the fall for winter storage.

Never tried StarTron though it gets good reviews on the web. I get seafoam by the case online much cheaper than at the parts stores.

 

I
I,ve been using Seafoam for a long time.

 

Except for storage or extreme cold, I see no need for fuel or oil additives. Assuming you change oil regularly.