Final answer:
The environmental act requiring an average of 2.71% ethanol in gasoline does not mandate that every gallon must include ethanol. Ethanol blends like E10, E15, or E85 can be used to achieve this average, with implications for fuel economy and vehicle compatibility. The use of ethanol and biodiesel is part of a strategy to reduce reliance on oil and emissions.
Step-by-step explanation:
The environmental act stating that gasoline must average at least 2.71% ethanol does not necessarily mean that each gallon sold has to contain ethanol. Instead, the average ethanol content across all gasoline sold in the country must meet or exceed this percentage. Often, ethanol is blended into gasoline in various concentrations such as E10 (10% ethanol), E15 (15% ethanol), and E85 (up to 85% ethanol). The use of ethanol in different percentages has implications for vehicle performance, fuel economy, and emissions. Ethanol has a lower energy density than gasoline, which can lead to a decrease in miles per gallon. Additionally, not all vehicles can handle higher ethanol blends such as E85, though these vehicles typically support lower blends like E10.
Fuel mandates, like the introduction of ethanol into fuel blends, are influenced by a variety of factors including environmental concerns, political motives, and economic interests. While ethanol can reduce dependence on oil and potentially lower emissions, it can also affect fuel economy. Flex-fuel vehicles can run on variable ethanol blends, balancing the benefits of ethanol's cleaner combustion with potential reductions in MPG.
Biodiesel is another alternative fuel produced from vegetable oils or animal fats and, like ethanol, it can lower certain pollutants when burned in comparison to petroleum diesel. Biofuels overall, including ethanol and biodiesel, are part of wider strategies to reduce fossil fuel usage and greenhouse gas emissions.