That seems like a great way to remove the alcohol from fuel - is alcohol that bad in the fuel that it's worth the trouble of removing it?niel_petersen said:In a test tube (or similar) put a small amount of water in the bottom, note the level of the water, and then fill the tube with a fuel sample. Put your thumb over the top and shake vigorously for several seconds and then let the water settle back to the bottom.
If there was ethanol present, the apparent volume of the water will have increased substantially. The water will "suck" any alcohol out of the fuel. The alcohol would much rather dissolve with the water than with the gasoline.
It works best if the initial ratio of water to fuel sample is about 1 to ten, but it isn't very critical. It is the test aircraft owners are using to detect alcohol, which is verboten in aircraft.
Maybe it would be ok to use in something low compression and cheap like a lawn mower, but not in any airplane or fuel injected engine. Who wants to guess what the residual octane might be?bjedruszczak said:That seems like a great way to remove the alcohol from fuel - is alcohol that bad in the fuel that it's worth the trouble of removing it?
My cars handle the poisoned gas pretty well, but there is a measureable loss in fuel economy of 3-4%. My power tools don't like it at all. My 25 year-old Troy built tiller had the fuel valve seals swell up so badly I couldn't turn the valve. I thought it was just old age until I ran a tank of non-ethanol gas through it and had the valve start working slick as new again. It took only one tank to undo the damage from the ethanol.andres said:By "alcohol" I assume we refer to ethanol and/or methanol, both of which are actually great performers in internal combustion engines as borne out by the methanol and ethanol fuelled racing engines. Both ethanol and methanol has significantly higher octane ratings than "pure" gasoline, and can therefore be used in engines with compression ratios much higher than would be possible with "pure" gasoline, whether fuel-injected or carburetted.
The engine needs however to be designed or adapted for operation on pure ethanol or methanol, specifically since alcohol has a much lower heating value than gasoline requiring lower air:fuel ratios and therefore an increased volume of fuel. Advantages of alcohol as a fuel include much improved cooling, cleaner combustion, and about 20% less carbon emissions.
The reason ethanol and methanol are prohibited in aviation fuel is due to alcohol's volatility that could result in a vapor lock at altitude, its incompatibility with certain rubber materials used in the fuel systems, phase separation at altitude that may cause dissolved water to condense out of solution, and the lower heating value that decreases the aircraft's range. All factors that are irrelevant for land use.
Today's vehicle engines are designed to accommodate the alcohol/gasoline blends in use, and typically a 10-15% ethanol blend has very little impact on a modern engine, if at all noticeable. The blend does raise the octane rating by about 3 points, but one would expect slightly increased fuel consumption (about 3%) and perhaps marginal power loss if the engine management system fails to compensate for the alcohol.
I haven't found any compelling reason yet to avoid alcohol blended fuels. I certainly notice no adverse effect using it in my LT or for that matter in any of the other vehicles, motorcycles and small engines.
It seems like I'm not getting as many miles per gallon as I used to on premium gas, without the ethanol. Seems like a reduction of about 10/15 %.andres said:I haven't found any compelling reason yet to avoid alcohol blended fuels. I certainly notice no adverse effect using it in my LT or for that matter in any of the other vehicles, motorcycles and small engines.
If you only lose 10% MPG running a fuel with 27% less energy per gallon, you are doing pretty well and likely violating the laws of physics! Watch out for the science police!!deanwoolsey said:I have owned three flex fuel vehicles. They run great on everything up to E85. In fact they produce maximum horsepower on the E85 because as stated above, the octane rating of alcohol is much higher than gasoline. This allows a greater advance in the timing and great horsepower. The problem is that the number of BTUs in a gallon of gasoline is higher then the number of BTUs in a gallon of alcohol. All my flex vehicles lost ten percent of their fuel mileage when running E85. So unless you are paying 10 percent less for the E85, it's costing you money to run it. Most modern engines will tolerate up to 15 percent alcohol in the fuel, but you will lose 3 to 5 percent in your fuel mileage. So it's just something to consider when you buy that mid-grade fuel. If it's ten percent alcohol, it needs to be 5 percent cheaper to break even on the mileage.
Yes, I would gladly run mid-grade 100 percent gasoline in my LT.
I ran 10% ethanol (95 Octane rating) in the LT for about 3 years, and suffered the same type of lag at take off while using it. Eventually gave up and paid the difference (+15c/litre) for the higher priced 100% petrol (95 Octane) and since then it purrs along, no lag or hesitation. The issue was there through summer and winter, at near sea-level conditions.Voyager said:As for my LT, I am not sure, but it developed a sag when starting out particularly in warmer weather at the same time that my last local station switched to ethanol. I can't be sure that the correlation indicates cause and effect, but I suspect the ethanol is related to the sag.
Advancing the timing has an extremely small effect on thermodynamic efficiency. The only way to change that measureably in a normally aspirated engine is to increase the compression ratio. I don't know of any production engines that can do that.deanwoolsey said:I think the reason I only lost 10 percent on mileage is the vehicle computer which adjusts the fuel mapping based upon alcohol content. So while the E85 has 27 percent less energy, the engine can use it more efficiently using higher timing, etc. Diesel has a bunch of energy in it, but I bet you'll get zero miles per gallon with a tank of that in your flex fuel car.
Unfortunately, I have no local source of real gasoline so I have to suffer the LT sag... I am hoping the drought will cause sufficient food shortages and price increases that our politicians will come to their senses and stop using food for fuel.cws said:I ran 10% ethanol (95 Octane rating) in the LT for about 3 years, and suffered the same type of lag at take off while using it. Eventually gave up and paid the difference (+15c/litre) for the higher priced 100% petrol (95 Octane) and since then it purrs along, no lag or hesitation. The issue was there through summer and winter, at near sea-level conditions.
My partner had similar issues in her Japanese built car (Honda CRV), which was designed to take ethanol blends, so refused to use it. She just bought a Subaru and can guarantee it will never see an ethanol blend go through the tank cap.