Alcohols are in fact added to many common gasolines to boost octane
rating. no since 1930's hot rod engine. from then on until the mid 50's, benzene was used by hot rodders. late 40's to early 60's AV/GAS was used for those engines needing unusually high octane rated fuel. Mid 60's on to mid 70's the gas companies sold the hot rodder's fuel. By the mid 70's, insurance company rates killed the need for high octane rated fuel. |
Well mod,
I give up. This is no more fun than trying to teach a pig to sing.... Matt modervador wrote: Thanks for the correction, I did indeed leave the word "rating" off of the end of that sentence (although "octane" is a common enough abbreviation for "octane rating"). I also should have not implied that methanol was commonly added to the gasoline that most people buy at the gas pump, ethanol being preferred because of lower toxicity and corrosivity. While ethanol and methanol may not be as effective as other compounds, the "blending number" of ethanol is 118, meaning when blended with gasoline it boosts octane rating more than suggested by its rating in pure form of 100 (R+M)/2. 10% ethanol can boost the octane rating by 3. Alcohols are in fact added to many common gasolines to boost octane rating. %mod% (JAXAshby) wrote in message ... mod knock it off. even 25% alcohol to gas hardly raises the octane ---------------- rating ------------------ at all. you have been reading 1940's Popular Mechanix mags again. tsk tsk Depends on the alcohol, but the most common added to gasoline are ethanol and methanol, each with octane numbers of 100 or so. They boost the octane. |
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oder, check your "facts". what you report is so far from what happened at the
time we can onl assume your parents were still in grade school, or that you personally learned to read just last year. (modervador) Date: 9/30/2004 1:26 PM Eastern Daylight Time Message-id: What I know is that what you say and what is true are often opposites, and that you sometimes can't read or count backwards from 1961 to 1960. What I'll say now is that I was addressing the question on the reasoning behind oxygenated gasoline. I do claim that it exists especially because of carbed engines initially, which I expanded upon to show how non-carbed engines also benefit. I never implied that the EPA accomodated car manufacturers on this issue, generally the opposite was true. The winter RFG (reformulated gasoline) program went into effect 1995, a year or two after the last carburetted new truck was sold in the US and 2 or 3 years after the last car. Plenty of carb'ed cars were on the road in big cities then, less now, but the program continues because of benefits even to fuel-injected vehicles. As for the CVCC, few if any gasoline engines got better mileage in comparable vehicles and it was listed by the EPA as #1 for 1977. It "sold poorer" (your words) even at the same time it was the only Honda car engine available in U.S. in the early 1980s, when Honda was expanding production and making great increases in car sales in the US. But you knew that, didn't you? What you don't know, or at least you haven't said correctly, is the history of automotive technology and the formulation of gasoline. %mod% (JAXAshby) wrote in message ... oder, they got poorer fuel mileage than catalytic converter engines, but you knew that didn't you? they also sold poorer partly because of their poor fuel mileage and more so because they were maintenance hogs. but you knew that, didn't you? are you *still* claiming that oxygenated gasoline exists because those carb'd engine -- few in number -- needed special fuel upon warm up, AND the EPA wanted to accomodate the car manufacturers? yeah, sure. whatever you say. (modervador) Date: 9/29/2004 11:07 AM Eastern Daylight Time Message-id: (JAXAshby) wrote in message ... Reduction of CO emissions during warm-up for carbureted engines. mum mum vador, knock it off. for all practical purposes there are no carbueted auto engines on the road for a very long time. I believe that last such sold as new was the miserable CVCC engine, and that was well more than 25 years ago. The carburetted CVCC engine's last year was 1985. By 1984 it was running closed-loop with feedback from an O2 sensor in the exhaust stream to maintain a stoichiometric mixture, so the "lean burning stratified charge" feature of the original CVCC was no longer being used although the head retained the pre-combustion chamber and carb retained the auxilliary 3rd barrel to feed the prechamber. The prechamber and 3rd barrel were done away with for 1986. The last year for the standard carbed Accord engine was 1989 (injection was an option starting in 1985) and the Civic models all got fuel injection in 1988 I think. But that's just the Hondas. There were plenty of other carbed engines made which are still around, both open-loop and closed-loop, and I don't care to dredge to find when the last one was sold new in the U.S., but it was more like 14 years ago and it likely wasn't a Honda. There are also open-loop fuel injection systems (no O2 sensor). With open loop, before the engine warms up, combustion is less controlled and the choke (or idle enrichment in FI) makes it run slichtly rich, increasing CO output. Even with closed loop, the design of the O2 sensor and engine management system is a factor. The O2 sensor does not send out a signal till it warms up, so the engine management system must run in open-loop mode till then, defaulting to slightly rich with elevated CO output. Many O2 sensors have a heating element to speed the warm-up of the sensor to decrease the time running open-loop. But then there's the catalytic converter, the final link. Till it warms up, it allows the CO to escape unconverted. Some catalytic converters are being designed to have heaters that decrease warm-up time. So even the most modern car has some period after a cold start, during which it runs open-loop and spews more CO than it does after warm-up. Oxygenated fuels increase the oxygen-to-hydrocarbon ratio during open-loop running and thus promote more complete combustion that produces CO2 rather than CO. In several metropolitan areas there remains a high proportion of older cars with carbs and early-version fuel injection systems. In winter months the warm-up time is increased during which these cars emit increased CO to an extent large enough that the EPA (or some other branch of gummint) has mandated oxygenated fuels during the coldest months in these areas. %mod% |
You are focusing only on high octane rated "hot rod" fuel, never
mentioned tetra-ethyl lead the discussion was regarding alcohol. tetra-ethyl lead came about from reaseach done by General Motors in 1920 on ways to improve the quality of gasoline ("normal" octane of the times were about 65, though 100 octane gasoline was produced -- at huge expense -- for WW1 aircraft engines). Several compounds were found to be useful increasing "octane rating" of gasoline without super-expense refining. The very best of those compounds was tetra-ethyl lead. The second best -- by some distance -- was a chemical still commonly used by farmers to reduce fungus growth on their crops [sorry I don't recall the name]. the GM vice-president in charge of the reasearch project left GM at project's end to form The Ethyl Corporation (apparently with GM's blessing). This was all reported in The Petroleum Institute of America Journal [Apr/May ? 1921?], an original copy of which I read in 1981. Find a copy and read it if you wish. |
Ethanol has tax incentives that can make it advantageous as an octane
booster even when oxygenation is not the primary goal. a commonly used farm fungicide -- available in 1981 for $70 for a 55-gallon drum, plus shipping, quantity one -- works far better on an ounce by ounce basis. I seem recall GM's research indicated that 1 ounce of that fungicide increased the octane rating of a gallon of gasoline by about 5 points. |
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