What is the purpose of mixing 10% ethanol with gasoline as a vehicle fuel?

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  • 6 years ago
    Favorite Answer

    This is an excellent question.

    The push for alcohol in gasoline came at a time of higher fuel prices and two threats. What you hear about most is the savings in emissions that using alcohol will provide. While alcohol does burn cleaner than gasoline it also does not contain as much energy. This slightly reduces the fuel economy while running on alcohol blends. In the balance there might be some emission savings at the car but this is most likely overbalanced by the factory like production of alcohol from farm products (which require lots of petrochemical fertilizers and petrochemical operated farm machinery.).

    We needed to take an essential additive out of gasoline: lead. It was demonstrated that lead in gasoline was (and residual amounts continue) to poison our environment. Lead was used in gasoline to increase its octane rating. A gasoline with a higher octane level can be compressed to a higher level. Internal combustion engines with a higher compression ratio can operate more efficiently (without pre-ignition or "knocking.")

    Finally when factory farmers realized the ethanol was a good substitute for lead and was cleaner burning they lobbied congress to mandate a minimum of 10% ethanol in all gasoline. And so we have ethanol in gasoline today mostly because it is an essential additive, because farmers wanted the market and because it could be sold to the American people as a "cleaner" alternative.

    If there is a moral to this story it is that just because something looks and feels "green" it is not necessarily better or "cleaner." The "devil is [always] in the details," and "green" like "natural" "organic" or even "healthy," are mostly terms used to market products rather than define them in any scientific way. Although I would prefer electric vehicles, I would rather ethanol in gasoline than lead.

  • John W
    Lv 7
    6 years ago

    It raises the octane.

    In the 70's, the US government introduced E15 as gasohol however the cars at the time often had natural rubber hoses and seals which dissolved in ethanol and they were are all carburetor engines which either requires a manual choke or changing the diameter of the jets to change the fuel to air ratio for the lower energy density of ethanol and most cars had water chokes ( automatic chokes based on coolant temperature ). This meant the engines ran lean and any rubber dissolved and many car owners who didn't first convert their cars, wound up with huge repair bills. Gasohol and ethanol got a bad reputation. But the government still wanted to reduce their reliance on imported oil so in the 80's, they required all new cars to be tolerant of fuel with up to 15% ethanol but they knew the public would not accept gasohol again so they passed a law ( yes an actual law ) that said that E10 could be sold as premium unleaded gasoline, this blended in with consumer demand to ban lead in gasoline. Early in the 80's, the cars were still carburetated so the manufacturers sized the jets to allow E10 through E15 fuel and simply printed "Use only Premium Unleaded Fuel" on the dash, the gas cap and in the manual. Later as fuel injected engines became popular, the engines could adjust to a wide range of fuel to air ratios as needed. During the 70's, Brazil had changed completely to ethanol which they produced from sugar canes and unlike Americans, they were bright enough to actually modify their cars for ethanol bu then sugar prices went up and the farmers sold to the world sugar market instead leaving Brazil in a fuel crisis which essentially halted their economy as they could not convert the vehicles back to gasoline fast enough so in the late 80's to early 90's, they asked the automobile manufacturers what could be done to make the cars flexible between the fuels. The car manufacturers knew that fuel injected cars could already use any combination of gasoline and ethanol so they agreed to develop such a product. They reprogrammed their regular cars to only allow up to 33% ethanol, beefed up the fuel lines and fuel filter as the US public was leery of ethanol and released cars that were programmed for up to 100% ethanol as flex cars at a premium cost even though they were the same cars and lobbied ythe government for E85. Now the bill that allowed E85 to be sold including the the clause that all fuel sold at a gas pump must have their ethanol content labelled but premium unleaded was already 10% ethanol and midgrade was premium mixed with regular so the solution was to attach labels saying "May contain up to 10% ethanol". The Bush administration then took credit for bringing in 10% ethanol to gasoline to say they were environmentally friendly.

  • 6 years ago

    Reduces emissions. Also reduces use of fossil fuels. Unfortunately, it is not as efficient as pure gasoline, and therefore reduces your car engine's output.

  • oikoσ
    Lv 7
    6 years ago

    Mainly to reduce emissions. It also helps keep the engine cleaner.

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  • Anonymous
    6 years ago

    DMT Reeeeal nice for grandpa

  • 6 years ago

    Alcohol is Renewable Source of power, that's why they do it.

    Source(s): systemic electric
  • 6 years ago

    To decrease your mileage and give you less power.

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