E85 is a flex fuel blend that contains 51% to 83% ethanol mixed with gasoline.
Ethanol-blended fuels like E85 can play a critical role in addressing climate change, but is E85 better for the environment?
This article examines the pros and cons of using E85 instead of gasoline.
Is E85 Better for the Environment?
E85 reduces greenhouse gas emissions and toxic air pollutants compared to gasoline, but it falls short of deep decarbonization.
With proper policies and safeguards, E85 can constructively contribute to lowering transportation emissions.
But it is only one piece of the puzzle, not a silver bullet.
Key Points
- E85 can reduce greenhouse gas emissions from vehicles by 20-50% on average once land use changes are factored in.
- E85 decreases tailpipe emissions of air toxins like benzene that are hazardous to human health.
- Expanding E85 is limited by the small number of gas stations offering it and the lower fuel economy compared to gasoline.
Does E85 Reduce Greenhouse Gas Emissions?
Compared to pure gasoline, E85 reduces greenhouse gas emissions by at least 50% or more.
The exact reduction depends on the ethanol content of the blend.
E85 does not contain petroleum, so its use decreases reliance on fossil fuels.
Since growing corn absorbs CO2 as it grows, ethanol from corn has the potential to approach carbon neutrality.
However, factors like the energy used to produce corn ethanol and changes in land use patterns can dampen its greenhouse gas reduction benefits.
What About Other Pollutants?
In addition to greenhouse gases, burning gasoline emits other pollutants like carbon monoxide, nitrogen oxides, and benzene that are hazardous to human health.
E85 produces lower evaporative emissions and emissions of toxic chemicals than pure gasoline or low-level ethanol blends.
Compared to gasoline, E85 poses a lower risk of cancer and other health problems.
However, increasing the use of E85 could also increase emissions of acetaldehyde and peroxyacetyl nitrate (PAN).
More study is needed on the human health impact of these pollutants.
Does E85 Help Reduce Oil Consumption?
E85 does displace petroleum, which helps reduce oil consumption and imports.
However, ethanol contains only about 70% of the energy of gasoline per gallon.
More frequent refueling is required, reducing the potential petroleum displacement.
Does the Use of E85 Increase Other Environmental Issues?
A study by Mark Jacobson of Stanford University found that increasing the use of E85 could increase ozone-related mortality, hospitalization rates, and asthma attacks.
However, ozone increases are more closely related to overall ethanol content rather than E85 specifically.
Lower ethanol blends may also increase ozone.
There are also concerns that nitrates from fertilizer could contaminate water supplies.
Cellulosic ethanol would help avoid this.
What Are the Cons of Using E85?
While promising in some regards, E85 also has some drawbacks:
- E85 may increase emissions of acetaldehyde and ground-level ozone compared to gasoline.
- More frequent refueling is needed due to the lower energy density per gallon of ethanol.
- Concerns exist about contamination of water supplies from corn production.
- Increases in corn production could displace other crops or expand agriculture into marginal lands.
- Today’s corn ethanol production relies heavily on fossil fuels for cultivation, harvest, and distillation.
- The net greenhouse gas reductions are only about 20-30% once land use changes from increased corn production are factored in.
- Economic and technical hurdles remain for commercializing cellulosic ethanol at scale.
Addressing these challenges will help maximize the climate benefits of expanding biofuel use.
Does E85 Help Reduce Emissions from Existing Vehicles?
E85 has the potential to reduce greenhouse gas emissions from the millions of flex-fuel vehicles already on the road in the US.
Here are some considerations for using E85 in existing vehicles:
- E85 can be used in any flex-fuel vehicle, providing an immediate option for reducing transportation emissions from these cars and trucks.
- But the proportional emissions reduction benefits depend on the amount of ethanol blending. Higher ethanol content provides larger reductions.
- Mileage may decrease by 10-30% due to the lower energy density of ethanol per gallon. More frequent filling-ups are needed.
- Cold starting issues may require switching back to gasoline in winter months.
- Consumers need convenient access to E85 pumps for this to be a practical option. Only about 3% of gas stations currently offer E85.
While reducing emissions from existing vehicles is beneficial, even larger benefits will come from developing more optimized flex-fuel vehicles and engines designed specifically for high ethanol blends rather than gasoline.
How Does E85 Stack Up to Electric Vehicles?
Both E85 and electric vehicles can help lower transportation emissions relative to gasoline-only internal combustion engines.
But how do they compare?
- Electric vehicles powered by clean electricity produce zero direct emissions and are 2-3x more energy efficient than combustion engines.
- But E85 has advantages in the use of existing infrastructure, lower vehicle costs, and convenience for long-distance travel.
- E85 is limited to emission reductions of 20-50% after land use impacts are considered. Electric vehicles enable deep decarbonization.
- Expanding E85 could help reduce emissions in the near term while electric vehicle technology continues improving.
- For light-duty vehicles, electrification is the clearest path to zero-emissions transportation. But for some heavy applications, high ethanol blends may provide the best option with renewable fuels.
Ideally, the growth of electric vehicles will be complemented by the continued evolution of lower-carbon renewable fuels like E85.
Can E85 Help Address Climate Change?
With transportation being a major contributor to greenhouse gas emissions, can expanding the use of E85 make a meaningful difference in addressing climate change?
- E85 reduces direct tailpipe emissions but only by about 20-50% overall once land use changes are factored in. Much larger reductions are needed.
- But ethanol fuels combined with efficiency measures could help reduce transportation emissions in the near term while more transformative technologies are scaled up.
- E85 is only one piece of the puzzle. We also need greater vehicle efficiency, travel demand management, smart growth, and electrification to achieve deep decarbonization of transport.
- Advanced renewable fuels like cellulosic ethanol and renewable diesel can build on the role of first-generation biofuels like corn ethanol.
- Any low-carbon fuel strategy needs strong sustainability safeguards to avoid unintended consequences.
With comprehensive policies and sustained innovation, E85 and other biofuels may play an important role in mitigating transportation emissions on the path to a zero-carbon future.
Is E85 Part of the Climate Solution?
E85 can contribute to lowering transportation emissions, but many factors determine its effectiveness and sustainability.
Here are the key points to keep in mind:
- The net emission reductions from displacing gasoline are real but lower than expected once land use impacts are considered.
- First-generation corn ethanol needs continuous improvement to reduce fossil energy use in production and optimize greenhouse gas balances.
- Advanced biofuels have greater potential if the challenges of commercialization can be overcome.
- Complementary policies are essential to ensure low carbon fuel standards, manage land use changes, and incentivize innovation.
- Any low-carbon fuel strategy should prioritize efficiency and conservation first before substituting alternative fuels.
- Biofuels are limited in their ability to enable deep decarbonization and need to be combined with other solutions.
With the right supporting policies and technologies, E85 can play a constructive role as part of a comprehensive approach to reducing transportation emissions.
But biofuels alone are not a climate panacea.
Is E85 a Sustainable Choice?
The use of biofuels like E85 raises questions about the balance between reducing greenhouse gas emissions and maintaining environmental sustainability.
- E85 does displace fossil fuels, but today’s corn ethanol has challenges in energy, water, and land use that limit its sustainability.
- Increasing corn production enough to meet a large share of fuel demand would require careful management to avoid depleting water resources, reducing biodiversity and fertilizer runoff.
- Cellulosic ethanol from wastes and dedicated crops like switchgrass can improve the sustainability balance but are not yet commercially viable at scale.
- Any low-carbon fuel strategy needs to emphasize improving efficiency first before substituting alternative fuels.
- Strong sustainability standards and innovation are needed to realize the promise of low-carbon biofuels while avoiding unintended consequences.
With proper safeguards and technology improvements, biofuels can play a role in reducing the carbon intensity of transportation while supporting other environmental goals.
But the transition will require getting the details right.
Is E85 Better for the Environment?
How does ethanol compare to gasoline in terms of environmental impact?
Ethanol has both advantages and disadvantages compared to gasoline in terms of environmental impact.
On the plus side, ethanol produced from renewable feedstocks can reduce reliance on fossil fuels and lower greenhouse gas emissions on a life cycle basis.
Ethanol contains oxygen which allows for more complete fuel combustion, reducing tailpipe emissions of carbon monoxide, nitrogen oxides, and air toxins compared to gasoline.
However, several factors can dampen ethanol’s environmental benefits.
Agricultural production of feedstocks like corn requires fossil fuel inputs for cultivation, harvesting, and refining.
And if carbon-rich land is converted to grow the feedstock, it can negate the greenhouse gas reductions.
Ethanol also has lower energy density than gasoline, requiring more frequent refueling.
Improving agricultural practices, utilizing waste products, and developing more energy-efficient ethanol production processes can help maximize the environmental benefits.
What are the environmental effects of E85 versus gasoline?
Using E85 as a replacement for gasoline provides several environmental advantages but also some potential drawbacks.
On the positive side, E85 reduces direct life cycle greenhouse gas emissions by at least 50% on average compared to gasoline depending on the ethanol content of the blend.
It also lowers tailpipe emissions of harmful air pollutants like benzene and 1,3-butadiene that pose ground-level.
However, increased use of E85 could contribute to higher emissions of acetaldehyde and ground-level ozone compared to gasoline.
And when impacts of increased corn production like soil erosion and fertilizer runoff are factored in, the net greenhouse gas reductions achieved with today’s corn ethanol are only 20-30%.
More study is needed to fully understand the environmental tradeoffs.
Cellulosic ethanol from wastes and dedicated energy crops may provide larger gains.
The Verdict: Is E85 Better for the Environment?
The use of ethanol fuel blends like E85 holds promise for reducing greenhouse gas emissions from transportation, but the devil is in the details.
Here’s the summary:
- E85 can directly displace petroleum and reduce tailpipe emissions of greenhouse gases and air pollutants. But land use impacts dampen the size of the reductions.
- First-generation corn ethanol needs continuous improvement in efficiency and sustainability. Advanced biofuels need accelerated commercialization.
- Strong policies are essential to manage tradeoffs, ensure sustainability, and spur innovation. Caution is required to avoid unintended consequences.
- Greenhouse gas reductions in the 20-50% range are valuable but insufficient. Much larger reductions are needed across all sectors to address climate change.
- Biofuels are one piece of the puzzle, not a silver bullet. Complementary solutions like vehicle efficiency and electrification remain essential.
With a proper perspective on its pros, cons, and limits, E85 can positively contribute to reducing transportation emissions in balance with other solutions.
But the hard work of improving vehicle technologies and creating sustainable fuel supplies is just beginning.
Frequently Asked Questions
What is the main benefit of E85 over gasoline?
E85 reduces direct tailpipe emissions of greenhouse gases by over 50% on average compared to pure gasoline. This helps mitigate climate change impacts from transportation.
Does E85 fully eliminate tailpipe emissions?
No. While lower than gasoline, E85 still produces tailpipe emissions from combustion in the engine including carbon dioxide, nitrogen oxides, and acetaldehyde. E85 cannot enable zero-emission transportation on its own.
Can E85 be made from waste?
Yes. Cellulosic ethanol produced from agricultural residues, forest waste, and dedicated energy crops could provide greater sustainability benefits compared to today’s corn ethanol. But it is not yet commercially viable at scale.
Here at GreenChiCafe, we are passionate about the environment and our natural world. We believe it’s important to carefully examine issues like biofuels and transportation emissions reduction strategies. Please check out our website for more content on building a sustainable future.
Annie is a passionate environmental writer and activist. She has been writing about sustainability, conservation, and green living for over 15+ years. Annie is dedicated to raising awareness about environmental issues and providing practical tips for living an eco-friendly lifestyle. When she’s not writing, you can find her volunteering with local environmental organizations, teaching workshops on zero waste living, or exploring nature. Feel free to get in touch with Annie: annie@greenchicafe.com