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Question of the Month: How can I compare the energy content of alternative fuels and gasoline or diesel? What implications does this have for overall fuel and vehicle comparisons?

April 26, 2017 by Clean Cities

Measuring Fuels: Understanding and Using Gasoline Gallon Equivalents
Alternative fuels have varying energy densities and are measured using a number of different units, which can make comparing them tricky. The gasoline gallon equivalent (GGE) unit allows drivers to make apples-to-apples comparisons of a given quantity of energy from alternative fuels and assess which fuel best suits their needs. Understanding the energy content of fuels can help inform comparisons of fuel prices and vehicle driving range.

What is a GGE? How about a DGE?

A GGE is a standardized unit used to compare the energy content of all fuels. This unit quantifies the amount of alternative fuel that has the equivalent energy content of one gallon of conventional gasoline. For medium- and heavy-duty vehicle fuel applications, diesel gallon equivalent (DGE) is often used.

How are GGE and DGE values determined?

Energy content is measured in British thermal units (Btus) per gallon of fuel, and is often referred to as the lower heating value of the fuel. To calculate GGE and DGE, the energy content of one gallon of gasoline or diesel is divided by the energy content of the comparison fuel. For example, conventional gasoline has an energy content of 116,090 Btus per gallon, while propane has an energy content of 84,250 Btus per gallon. As such, 1.38 gallons of propane has the same amount of energy as one gallon of conventional gasoline.

The table below displays the energy content, GGE, and DGE values of conventional and alternative fuels.


Energy Content*

Quantity of Fuel in 1 GGE

Quantity of Fuel in 1 DGE

Gasoline 116,090 Btu/gallon 1.00 gallon 1.11 gallon
Low Sulfur Diesel 128,488 Btu/gallon 0.90 gallon 1.00 gallon
Biodiesel (B20) 126,700 Btu/gallon 0.92 gallon 1.01 gallon
Biodiesel (B100) 119,550 Btu/gallon 0.97 gallon 1.07 gallon
Compressed Natural Gas (CNG) 923 Btu/cubic foot (ft3)
20,160 Btu/lb
125.77 ft3
5.76 lb
139.21 ft3
6.37 lb
Liquefied Natural Gas 21,240 Btu/lb 5.47 lb 6.05 lb
Ethanol (E100) 76,330 Btu/gallon 1.52 gallon 1.68 gallon
Ethanol (E85)** 88,258 Btu/gallon 1.32 gallon 1.46 gallon
Electricity*** 3,414 Btu/kilowatt hour (kWh) 34.00 kWh 37.64 kWh
Propane 84,250 Btu/gallon 1.38 gallon 1.53 gallon
Hydrogen 288.88 Btu/ft3
51,585 Btu/lb
401.86 ft3
2.25 lb
444.78 ft3
2.49 lb

* Lower heating value. Source for CNG and hydrogen (Btu/ft3): Transportation Energy Data Book, Edition 35. Source for remaining values: Alternative Fuels Data Center (AFDC) Fuel Properties.

** E85 that is sold in the United States today actually contains, on average, approximately 70% ethanol. Therefore, E85 energy content calculated as [(.70) x (E100 energy content)] + [(.30) x (gasoline energy content)]

*** Electric vehicles are more efficient (on a Btu basis) than combustion engines, which should be taken into account when calculating and comparing miles per GGE (see below).

The values in the table above can help standardize fuel amounts for comparisons. For example, if you have 10,000 ft3 of CNG, you can determine the equivalent number of GGEs by dividing by 125.77 ft3 to get 79.5 GGE. Similarly, to determine the number of DGEs, you would divide by 139.21 ft3 to get 71.83 DGE.

How are GGE and DGE used to compare fuel prices?

Fuel prices can be represented in dollars per GGE or DGE for consistency in pricing between fuels. For that reason, the Clean Cities Alternative Fuel Price Report shows prices on an energy-equivalent basis (Table 3 in recent reports). If values for price per GGE or DGE are not available, you can do the calculation on your own. For instance, if one gallon of E85 is $2.04, you would multiply by 1.32 (see table above ) to find that this price equates to $2.69 per GGE after adjusting for energy content.

What are the factors that impact how far I can drive between fill ups?

The energy content of fuels is one factor that affects driving range. Filling up with a less energy-dense fuel often means that you will not be able to drive as far. However, tank size and vehicle efficiency also play a significant role.

Some alternative fuel vehicles (AFVs) have similar tank sizes to conventional vehicles, while others have larger fuel tanks to compensate for the difference in energy content. For example, vehicles that run on propane and biodiesel typically have similarly sized fuel tanks as their conventional fuel counterparts. As you can see in the table above, both of these fuels have lower energy densities than their conventional fuel counterparts, which subsequently can result in lower fuel economy and shorter range per tank. In the case of propane, bi-fuel vehicles are available that can operate on both conventional fuel and propane for extended driving range. In addition, propane and biodiesel offer many other benefits that can offset this difference.

CNG and hydrogen vehicles, on the other hand, often have larger tanks to offset the lower energy densities associated with these fuels. Fleets and drivers purchasing a CNG vehicle may have the option to install an additional CNG storage tank onboard the vehicle. Alternatively, bi-fuel CNG vehicles are also available to extend the range. As for hydrogen, these vehicles tend to have larger fuel tanks overall.

Tank size is not the only other factor that affects range; vehicle efficiency also plays a role. For instance, all-electric vehicles (EVs) are significantly more efficient than conventional gasoline vehicles. According to, EVs use anywhere from 59% to 62% of the electricity from the grid to power the vehicle, while conventional gasoline vehicles can only convert 17% to 21% of the energy from gasoline to power the vehicle. This is one reason why EVs have such significant fuel economy advantages over conventional vehicles, even when you are comparing the fuels on an energy-equivalent basis.

For more information, contact:

Clean Cities Technical Response Service Team

Question of the Month: What are state and local governments doing to incentivize alternative fuels and alternative fuel vehicles (AFVs)?

March 3, 2017 by Clean Cities

There are many notable incentive activities at the state and local levels. Many states offer incentives for alternative fuels that advance specific environmental and energy security goals, while cities provide even more localized support.

States are targeting vehicles, infrastructure, and other means to encourage AFV adoption. Below are various types of incentives, as well as hyperlinked examples of each:

  • AFV Purchase Incentives: States offer grants, rebates, and tax credits for the purchase of AFVs. While some states may focus vehicle incentives on a particular fuel type, such as electric vehicles, others are more general in their support. States provide AFV purchase incentives to consumers, commercial fleets, and public fleets, such as schools and government agencies. Different incentive mechanisms tend to be more appropriate for different categories of vehicle purchasers; for example, grants are often limited to certain types of entities. Public fleets may not be liable for taxes, so they usually benefit more from grants than from tax credits. Private fleets can benefit from grants, rebates, and tax credits.
  • Fueling Infrastructure Purchase and Installation Incentives: Similar to AFV incentives, states provide grants, rebates, and tax credits for alternative fueling infrastructure. States usually create incentives for the physical fueling infrastructure, but many programs also support installation costs. Some states also offer a tax credit or tax reduction for the production or purchase of alternative fuel itself. Fueling infrastructure incentives may stipulate that the fueling or charging station must be available to the public, which helps to increase the availability of alternative fuels to a broader range of entities.
  • Other Incentives: In addition to financial support for the purchase of AFVs, states may give special benefits to AFV drivers. For example, some states allow high-occupancy vehicle lane access to AFVs, while others provide reduced registration fees, weight restriction exemptions, and emissions inspections exemptions.

Municipalities are also playing a role in supporting AFV deployment. Cities and counties incentivize AFVs in a number of ways, including by offering free or discounted parking, expediting permitting processes, and providing vehicle and infrastructure grants. For example, New Haven, CT, provides free parking on city streets for AFVs, while Los Angeles, CA, offers instant, online residential electric vehicle supply equipment permitting approval. The Alternative Fuels Data Center’s (AFDC) Local Laws and Incentives page provides more information on these and a greater array of other local options; while the page regarding local laws and incentives is not meant to be comprehensive, it provides users an idea of the different municipal programs and policies that exist ( If you are aware of an innovative way that municipalities are supporting alternative fuels and vehicle acquisition, please contact the Clean Cities Technical Response Service at to share the details.

For more information about state and local alternative fuel incentives, see the AFDC Laws and Incentives page (

Clean Cities Technical Response Service Team

Question of the Month: How is the propane industry improving the customer fueling experience through new technology?

January 30, 2017 by Clean Cities

As propane vehicle technology becomes more advanced, propane dispensing infrastructure has evolved along with it. In particular, the propane industry is focusing much of its attention on enhancing the customer fueling experience by installing propane dispensers that are dedicated for vehicle fueling, and by upgrading the propane nozzle technology. The increasingly popular European-style, quick-connect nozzle simplifies the customer fueling experience by connecting to the fuel tank through a snap or quick-connect attachment, rather than a conventional threaded connection. Only after the nozzle is safely connected to the fuel tank will it begin to dispense fuel. This attachment eliminates the threading connection necessary with the conventional Acme nozzle, making propane fueling as easy as conventional gasoline fueling.

With the new nozzle, fueling can be completed using only one hand and without wearing protective goggles and gloves. The quick-connect attachment also results in lower emissions, as it more effectively prevents the release of fuel vapor and fumes. Additionally, the nozzle’s design minimizes the amount of fuel that escapes when the vehicle is done fueling and the connector is detached from the vehicle.

There are many affordable quick-connect nozzle options available on the United States market that meet UL 125 certification requirements ( Manufacturers of these UL-certified nozzles include Stäubli and ELAFLEX. These European-style connectors are priced around $1,200, according to the National Renewable Energy Laboratory ( The cost of the connection adapters, or fill valves, required for current fueling infrastructure to be compatible with the European-style nozzle, ranges from $50 to $60. Note that the installation of a new fueling nozzle should always be performed by a qualified technician in order to ensure that it is completed properly.

Many propane retailers are optimistic about the European-style, quick-connect nozzle. In fact, the Propane Education Research Council (PERC) highlights its benefits and encourages the use of this connector through its Quick-Connect Nozzle Incentive Program ( Moving forward, the quick-connect nozzle is a significant step towards streamlining and improving the propane fueling experience.

For more information about propane and related fueling infrastructure, see the following resources:


Clean Cities Technical Response Service Team

Volkswagen Partial Consent Decree Overview

January 11, 2017 by Clean Cities

The Clean Cities Technical Response Service, as a result of questions and inquiries related to the 225 page “Volkswagen Partial Consent Decree” released by the U.S. Department of Justice, has produced the following information that provides a general summary of critical information included in the package along with links to important documents:

VW “Clean Diesel” Consent Decree: The Basics

  • Consent Decree between the U.S., California and VW et al. (Settling Defendants) re: VW 2.0L TDI settlement program
  • June 28, 2016, filed with the Court by Dept. of Justice, on behalf of EPA and State of California
  • July 6, 2016 Federal Register Notice set in motion.
  • 3 parts:
    • $10 billion + (estimated) for VW customers; 2.0 L diesel vehicle buyback/lease termination
    • $2.7 Billion Environmental Mitigation Trust Fund
    • $2 Billion ZEV Investment Commitment

$2.7 Billion Environmental Mitigation Trust Fund

  • $900 Million to be deposited by VW et al. into Trust Account not later than 30 days after the effective date.
  • 2 additional $900 Million deposits by VW et al. into Trust Account, not later than the 1st and 2nd anniversaries of the initial deposit.
  • Allocated among states, Indian tribes and Puerto Rico on a % basis to fund actions that will reduce NOx emissions where the 2.0 L Subject Vehicles were, are or will be operated.

$2 Billion ZEV Investment Commitment over 10 years

  • National ZEV Investment Plan
    • Developed by VW et al.; approved by EPA, which has sole authority for making decisions.
    • $1.2 Billion in four 30 month investment cycles for U.S., except California
  • California ZEV Investment Plan
    • Developed by VW et al.; approved by CARB, which has sole authority for making decisions.
    • $800 million in four 30 month investment cycles for California

$2.7 Billion Environmental Mitigation Trust Fund

  • Goal: Achieve reductions of NOx emissions in the United States.
    • (GHG emissions not addressed.)
  • Beneficiaries: States, Indian Tribes, D.C., Puerto Rico
  • $2.7 Billion over 3 years for Eligible Mitigation Actions.
    • Eligible Vehicle Classes/Equipment:
      • Class 8 Local Freight Trucks, Port Drayage Trucks
      • Class 4-8 School, Shuttle or Transit Bus
      • Freight Switchers
      • Ferries/Tugboats (marine)
      • Ocean Going Vessels Shorepower
      • Class 4-7 Local Freight Trucks (Medium Trucks)
      • Airport Ground Support Equipment
      • Forklifts
      • LD ZEV Supply Equipment
        • L1, L2 or fast charging equipment
        • LD hydrogen fuel cell vehicle supply equipment
      • DERA Option – Beneficiaries may use Trust Funds for non-federal match.
        • Use of funds as match for other Federal funding opportunities is uncertain (not mentioned).

Eligible Actions For HD and MD vehicles, freight switchers, ferries, tugboats

  • Repower with:
    • New diesel engine, including costs of installing engine
    • New Alternate Fueled (CNG, propane, Hybrid) engine, including costs of installing engine
    • New All-Electric engine/motor, including costs of installing engine and charging infrastructure*
  • Replace with:
    • New diesel vehicle
    • New Alternate Fueled (CNG, propane, Hybrid) vehicle
    • New All-Electric engine/motor, including costs of installing engine and charging infrastructure*
  • Funding % for each action ranges from 25% – 100% and varies based on ownership (government or non-government owned) and type of action.
  • Funding is allocated by State. See Table on page 207 of Appendix D-1 in the Partial Consent Decree

*Infrastructure for other Alternative Fuels not eligible. Other Eligible Actions

  • Ocean Going Vessel (OGV) Shorepower
    • Costs of shore-side system, including cables, cable management systems, shorepower coupler systems, distribution control systems and power distribution components
  • Airport Ground Support Equipment
    • Repower or replace with all-electric engine/motor
  • Forklifts
    • Repower or replace with all electric engine/motor
  • Light Duty ZEV Supply Equipment
    • Beneficiary may use up to 15% of its allocation of Trust Funds for acquisition, installation, operation and maintenance of new LD ZEV supply equipment for specific public applications.
      • L1, L2 or fast charging equipment in a public place, workplace or multi-unit dwelling

Beneficiaries may use Trust Funds for actual administrative expenditures associated with implementing Eligible Mitigation Actions (not to exceed 10% of total cost of such Actions):

  • Personnel, including employee salaries and wages, but not consultants
  • Fringe benefits
  • Travel by program staff
  • Equipment with a useful life of > 1 year and acquisition cost >= $5,000
  • Supplies purchased in support of the Mitigation Action, such as educational publications, office supplies, etc. Contractual
    • Contracts for evaluation and consulting services and contracts with sub-recipient organizations are included. Construction
  • Other costs, including insurance, professional services, printing and publication, training and accounting


  • Each Governor’s Office or analogous Chief Executive must file a Certification Form with the Court to become a beneficiary and to receive funding, not later than 60 days after the Trust Effective Date.
  • Failure to file Certification Form will result in that state being an Excluded Entity, permanently enjoined from asserting any right to Trust Assets.
  • Each Beneficiary must notify any Federal agencies that control land within its jurisdiction (Interior, Agriculture, etc.) that they may request Eligible Mitigation Action funds for use on those lands.
  • Beneficiaries may submit request for 1/3 of allocated funds each year, for 3 years.

Beneficiary Mitigation Plan must be submitted not later than 30 days after being deemed a Beneficiary, and must include:

  • Overall goal for use of funds
  • Categories of Eligible Mitigation Actions to be undertaken
  • Description of potential benefit of Eligible Mitigation Actions on air quality in areas that bear a disproportionate share of the air pollution burden within its jurisdiction
  • General description of expected ranges of emissions benefits (NOx) to be realized by implementation of Beneficiary Mitigation Plan
  • Plan must designate a lead agency that will have the delegated authority to act on behalf of Beneficiary.
  • Beneficiary must explain process by which it shall seek and consider public input on its Beneficiary Mitigation Plan.
  • DERA Option: A Beneficiary may use its Final Approved DERA Workplan as its Beneficiary Mitigation Plan, and may use Trust Funds for actions not specifically enumerated in the Consent Decree, but otherwise eligible under DERA.

$2.0 Billion ZEV Investment Commitment

Zero Emission Vehicles include:

  • Battery electric vehicles (BEVs) and fuel cell vehicles (FEVs)
  • On-road plug-in hybrids (PHEVs) with zero emission range > 35 miles
  • On-road heavy duty vehicles with electric powered takeoff

Not Included:

  • ZEV off-road equipment and vehicles
  • Zero emission light rail
  • Additions to transit bus fleets using existing catenary electric power
  • Vehicles not capable of being licensed for use on public roads

ZEV Investment

  • Investment of money by VW et al. that promotes and advances the use and availability of ZEVs within the categories of actions set forth in consent decree

ZEV Investments May Include:

  • Design/planning, construction/installation, operation and maintenance of ZEV infrastructure
    • L2 charging at multi-unit dwellings, workplaces and public sites
    • DC fast charging facilities accessible to all vehicles utilizing non-proprietary connectors
    • New heavy-duty ZEV fueling infrastructure (in CA)
    • Later generations of charging infrastructure
    • ZEV fueling stations

ZEV Investments May Also Include:

  • Brand-neutral education or public outreach that builds or increases public awareness of ZEVs
  • ZEV car sharing services, ZEV ride hailing services, including ZEV autonomous vehicles
  • California’s “Green City” initiative
    • Includes operation of ZEV car sharing services, zero emission transit applications and zero emission freight transport projects.
    • Selection of the city will be made by VW et al., in consultation with appropriate local authorities in CA.

Public Comment:

  • Within 15 days after the Effective Date, VW et al. shall submit to EPA for review and approval a National ZEV Outreach Plan that includes a description of how they will provide States, municipal governments, Tribes and federal agencies with notice and opportunities to provide suggestions, observations and offers of assistance or support for actions they may take under the National ZEV Investment Plan.

VW “Clean Diesel” Consent Decree: Recap

Timing and Next Steps

  • 30-day public comment period on Consent Decree ends August 5, 2016.
  • Governors’ Offices and Tribal Governments must do the following:
    • File Certification Form to become Beneficiaries, no later than 60 days after the Trust Effective Date
    • Submit a Beneficiary Mitigation Plan no later than 30 days after being deemed a Beneficiary
  • Stakeholders, local government fleet operators and other interested parties should start working with Governor’s offices and relevant planning agencies as soon as possible, to discuss potential project ideas and partnering opportunities.
  • Selection of Trustee for Environmental Mitigation Trust Fund ($2.7 Billion)
    • Not later than 30 days after the Effective date, California, the States and Puerto Rico and Indian tribes must confer with each other and submit to the U.S. a list of 3-5 recommended trustee candidates. The U.S. may consider additional trustee candidates.
    • The U.S. will file a motion with the Court requesting that the Court select and appoint a trustee from among the recommended candidates.

For more information:

Question of the Month: How is fuel economy determined and reported for alternative fuel vehicles?

December 22, 2016 by Clean Cities

Last month we learned about how the U.S. Environmental Protection Agency (EPA) determines and reports conventional light-duty vehicle fuel economy ratings. While alternative fuel vehicle (AFV) fuel economy testing is largely similar to that of conventional fuels, the EPA makes some adjustments to account for different vehicle technology and fuel energy content. By tailoring AFV fuel economy testing and reporting, the EPA is able to provide apples-to-apples comparisons and allow consumers to make informed decisions.


All-Electric Vehicles

What’s Reported: The fuel economy label for all-electric vehicles (EVs) includes all of the same information as that listed for gasoline vehicles (fuel economy, fuel cost savings, annual fuel cost, and emissions). However, EV labels list fuel economy using miles per gallon of gasoline-equivalent (MPGe), sometimes referred to as miles per gasoline gallon equivalent (MPGGE). MPGe represents the number of miles a vehicle can go using a quantity of fuel with the same energy content as a gallon of gasoline. MPGe is a useful way to compare gasoline vehicles with vehicles that use fuel not dispensed in gallons. EV labels also include the following information:

  • Vehicle Charge Time: Indicates how long it takes to charge a fully discharged battery using Level 2, 240-volt electric vehicle supply equipment.
  • Driving Range: Estimates the approximate number of miles that a vehicle can travel in combined city and highway driving before the battery must be recharged.
  • Fuel Consumption Rate: Shows how many kilowatt-hours (kWh) of electricity an EV would use to travel 100 miles. Like gallons per 100 miles, the kWh per 100 miles relates directly to the amount of fuel used. It is an estimated rate of consumption rather than economy (measured in miles per gallon [MPG] or MPGe), which allows for more accurate energy usage comparisons between vehicles.

What’s Tested: To test EV fuel economy, the vehicle battery is fully charged and the vehicle is parked overnight. The next day, the vehicle is tested over successive city cycles until the battery is depleted. The battery is then recharged and the energy consumption of the vehicle is determined by dividing the kWh of energy needed to recharge the battery by the miles traveled by the vehicle. MPGe is based on this figure. The process is repeated for highway driving cycles, and the combined city and highway fuel consumption and MPGe is based on the standard ratio of 55% city and 45% highway driving.

Plug-in Hybrid Electric Vehicles

What’s Reported: Like EVs, plug-in hybrid electric vehicle (PHEV) fuel economy labels include fuel cost savings, annual fuel cost, and emissions information. For PHEVs that can use either electricity or gasoline (but only one fuel at a time), also known as non-blended or series PHEVs, labels include information for the fuel economy of both fuel modes. The electricity information is identical to that of EVs, listing charge time, fuel economy in MPGe, and fuel consumption rate in kWh per 100 miles. The gasoline information provides fuel economy in MPG and fuel consumption information in gallons per 100 miles. PHEV fuel economy labels also include electricity only, gasoline only, and combined electricity and gasoline driving range estimates. For PHEVs that use electricity and gasoline at the same time, also known as blended or parallel PHEVs, fuel economy labels reflect the fuel economy, fuel consumption, and range of the vehicle when it uses its standard electricity and gasoline mix.

What’s Tested: Because series PHEVs can use either electricity or gasoline, the EPA determines a vehicle’s fuel economy and fuel consumption based both on its use of only electricity and only gasoline. To determine a PHEV’s electric fuel economy, the EPA issues testing methodology nearly identical to that of EVs. If the gasoline engine is required to complete the test cycle, the EPA methodology uses both the electric energy consumption and the gasoline consumption to calculate the MPGe values for the electric operation only. Vehicle testing for the gasoline operation of the vehicle is similar to any other conventional hybrid electric vehicle. Parallel PHEVs are tested using their standard mix of electricity and gasoline.

Other Alternative Fuels

What’s Reported: The EPA also requires fuel economy information for original equipment manufacturer (OEM) vehicles that use alternative fuels. This includes dedicated natural gas, propane, and hydrogen vehicles, as well as bi-fuel vehicles, such as bi-fuel natural gas, propane, and flexible fuel vehicles (vehicles that may use 51%-83% ethanol-gasoline blends). Note that the EPA does not require fuel economy testing of vehicles converted to run alternative fuels after they are purchased. While the EPA does not list fuel economy information for vehicles that use biodiesel, all diesel vehicles may use fuel blends of up to 5% biodiesel. These vehicles achieve fuel economy very similar to conventional diesel.

For vehicles that use exclusively alternative fuels (e.g., natural gas or hydrogen), the EPA lists fuel economy in MPGe in order to accurately reflect the fuel’s energy content and make easy comparisons with conventional fuel vehicles. Vehicles that can use either alternative fuels or conventional fuel, such as bi-fuel natural gas, bi-fuel propane, and flexible fuel vehicles, have fuel economy, fuel consumption, and range estimates for both the alternative and conventional fuel listed on their fuel economy labels. Fuel economy for alternative fuel use in bi-fuel and flexible fuel vehicles is listed in MPGe, while fuel economy for conventional fuel use is listed in MPG.

What’s Tested: For vehicles that run exclusively on alternative fuels, fuel economy testing methods are similar to those of conventional vehicles. For bi-fuel and flexible fuel vehicles, the vehicle fuel economy is tested as it runs exclusively on each fuel, similar to PHEVs.

For more information about AFV fuel economy, see the website ( and select from the Advanced Cars & Fuels menu. Also, view the Fuel Economy Toolkit (

Happy Holidays!


Clean Cities Technical Response Service Team

What are the current and future medium- and heavy-duty vehicle fuel efficiency and greenhouse gas emissions standards?

October 10, 2016 by Clean Cities

According to the U.S. Environmental Protection Agency (EPA) and the National Highway Traffic Safety Administration (NHTSA), greenhouse gas (GHG) emissions from medium- and heavy-duty vehicles (collectively, HDVs) are expected to surpass light-duty vehicle (LDV) emissions by 2030. The Energy Independence and Security Act of 2007 directed the U.S. Department of Transportation to establish fuel efficiency standards for HDVs. Then, in 2010, President Obama announced a new national program to implement coordinated fuel efficiency and GHG emissions standards for medium- and heavy-duty engines and vehicles. As you may have seen last month, EPA and NHSTA recently finalized the most recent set of requirements under this program.

First promulgated by EPA and NHTSA in 2011, these coordinated standards are being implemented in two separate phases, beginning with Model Year (MY) 2014 to 2018 (Phase 1, which has now been extended through 2020) and followed by MYs 2021 to 2027 (Phase 2), with some exceptions. Under Phase 1, the GHG emissions and fuel efficiency standards generally increase in stringency in MY 2017, then remain steady through MY 2020. GHG emissions and fuel efficiency standards under Phase 2 of the program increase first in MY 2021, and then again in MYs 2024 and 2027. Although the Phase 2 standards do not begin until MY 2021, manufacturers may need to begin compliance measures beforehand in order to be adequately prepared to meet the targets.

Fuel efficiency and GHG emissions standards are determined differently for each of five regulated heavy-duty (HD) engine and vehicle categories: combination tractors; vocational vehicles; HD engines used in combination tractors and vocational vehicles; trailers used with combination tractors; and HD pickup trucks and vans. For more information on these categories, please refer to pages 3 and 4 of the EPA Phase 2 fact sheet (

NHTSA Fuel Efficiency Standards

NHTSA’s fuel efficiency standards are designed to take into account the different functions of each of the regulated vehicle categories. Therefore, the standards are calculated differently for each vehicle category. For HD pickup trucks and vans, there are separate gasoline and diesel target values.

The vehicle-based standards for combination tractors and vocational vehicles are calculated based on weight class, as well as specific characteristics of the vehicle category that affect fuel consumption and emissions, such as roof height for combination tractors and drive cycle for vocational vehicles.

The HD engine standards are determined by the size of the engine, the fuel type (diesel or gasoline), and the characteristics of the respective vehicles into which they are installed. The HD pickup and van standards, engine and chassis included, are fleet-average standards based on fuel-specific (gasoline and diesel) target values that are determined by a “work factor” curve. The “work factor” curve takes into account the payload and towing capacity of the vehicle and whether the vehicle has 4-wheel drive. Like the Corporate Average Fuel Economy (CAFE) program for LDVs, the HD pickup and van targets are production-weighted based on the manufacturer’s total sales volume of all of its different HD pickup and van models.

Compliance Timeline

Manufacturers were required to meet Phase 1 fuel efficiency standards for combination tractors, vocational vehicles, and HD engines beginning either in MY 2016 or 2017. Phase 2 standards apply in MY 2027, with phase-in standards for MYs 2021 and 2024. Trailer fuel efficiency standards are voluntary beginning in MY 2018, and mandatory effective MY 2021. Manufacturers were not required to participate in the Phase 1 HD pickup and van program until MY 2016. At the outset of the program, NHTSA gave manufacturers the option to choose one of the alternative phase-in options for the Phase 1 standards. Phase 2 HD pickup and van standards begin in MY 2021 and increase in stringency by 2.5% each model year through MY 2027.

Fuel Efficiency Standards and Targets

To view the final Phase 1 standards and HD pickup and van targets, please see the Phase 1 Final Rule. For the recently finalized Phase 2 standards and targets, see the Phase 2 Final Rule. You may also reach out to TRS directly ( if you would like specific information about where to find the finalized standards.

EPA GHG Emissions Standards

EPA also takes into account the varying functions of each of the regulated vehicle categories in its GHG emissions calculation. It uses the same factors as NHTSA to determine emissions standards for each vehicle category, except measurements are based on grams of carbon dioxide (CO2) emitted.

Compliance Timeline

EPA’s mandatory Phase 1 GHG emissions standards for combination tractors, vocational vehicles, and HD engines began in MY 2014. The timeline for the Phase 2 standards mirrors that of the NHTSA fuel efficiency standards. However, Phase 2 trailer emissions standards differ in that they are mandatory in MY 2018. For Phase 1 of the HD pickup truck and van program, similar to the fuel efficiency targets, manufacturers were given the option to choose from two alternative phase-in options. As with the Phase 2 fuel efficiency targets, the separate GHG emissions targets for diesel and gasoline HD pickups and vans will increase in stringency under Phase 2 by 2.5% per year from MY 2021 to 2027.

Emissions Standards and Targets

GHG emissions standards and targets for Phase 1 and Phase 2 can be found in their respective final rules. Please refer to the Fuel Efficiency Standards and Targets section above for more information.


Manufacturers may employ many different compliance measures to meet the fuel efficiency and GHG emissions standards. These measures vary depending on the vehicle category. Each vehicle category has a different certification testing process to determine its GHG emissions and fuel efficiency values. These values are the baseline to which any additional earned credits can be added. The regulation also offers incentives to encourage advanced vehicle technologies

The credits and incentives available for both the EPA and NHTSA programs include:

  • Advanced Technology Credits: Phase 1 of the program incentivizes manufacturers to produce advance technology vehicles and engines by effectively allowing manufacturers to “count” certain vehicle and engine types as more than one in their compliance calculations. This includes vehicles with hybrid powertrains and Rankine-cycle waste heat recovery systems, as well as plug-in electric vehicles (PEVs) and fuel cell electric vehicles (FCEVs). As the new Phase 2 standards are premised on some use of Rankine-cycle engines and hybrid powertrains, these technologies will not qualify as advanced technologies under Phase 2. From MY 2021 through MY 2027, advanced technology credits (with considerably higher multipliers) will only be offered for PEVs and FCEVs.
  • Innovative Technology and Off-Cycle Credits: Both Phases 1 and 2 of the program allow manufacturers to earn credits for off-cycle technologies that result in benefits that are not captured in certification testing procedures.
  • Early Credit Multipliers: Phase 1 of the program enabled manufacturers to earn credits for early compliance. Phase 2 will not include early credits.

For more information on the medium- and heavy-duty engine and vehicle GHG emissions and fuel efficiency standards, please refer to the following resources:

Clean Cities Technical Response Service Team


What are the current and future light-duty vehicle fuel economy and greenhouse gas (GHG) emissions standards

October 3, 2016 by Clean Cities

According to the U.S. Environmental Protection Agency (EPA), light-duty vehicles (LDVs) emit nearly 60% of transportation-related GHG emissions and use more than half of all petroleum transportation fuel in the United States. In 1975, Congress enacted the Energy Conservation and Policy Act, which directed the U.S. Department of Transportation (DOT) to implement the Corporate Average Fuel Economy (CAFE) program. The goal of the CAFE program is to reduce national energy consumption through fuel economy improvements. Specifically, the National Highway Traffic Safety Administration (NHTSA), as part of DOT, develops annual fuel economy requirements for new passenger cars and light-duty trucks. Fuel economy is measured based on the average mileage a vehicle travels per gallon of gasoline, or gallon of gasoline equivalent for other fuels.

In 2009, President Obama announced a new national program to harmonize fuel economy standards with GHG emissions standards for all new light-duty cars and trucks sold in the United States. Under this program, the U.S. Environmental Protection Agency (EPA) develops GHG emissions standards that correspond with NHTSA CAFE standards for each model year (MY). Thus far, the EPA and NHTSA have implemented the program in two parts, beginning with MYs 2012 to 2016 and followed by MYs 2017 to 2025. GHG emissions and CAFE standards have become increasingly stringent from one MY to the next.

In the final rule that established the coordinated standards for MYs 2017 to 2025, the EPA and NHTSA committed to perform a midterm evaluation (MTE) to (i) determine whether any changes should be made to the GHG emissions standards for MY 2022 to 2025, and (ii) set final CAFE standards for those MYs. This past July, the EPA and NHTSA completed the first step of the MTE with their issuance of a draft technical assessment report. For more information on the MTE, please see the EPA Midterm Evaluation of Light-Duty Vehicle GHG Emissions Standards page ( and the NHTSA Midterm Evaluation for Light-Duty CAFE page (

NHTSA CAFE Standards

NHTSA determines CAFE standards based on each vehicle’s size, or its footprint, which is essentially the distance between where each of its tires touches the ground. In general, the larger the vehicle is, the less stringent the fuel economy target will be. NHTSA then calculates each manufacturer’s fleet-wide compliance obligation, which is weighted based on vehicle sales (e.g., if 15% of a manufacturer’s sales are one model, that model gets a “weight” of 0.15 in average fuel economy calculation), each vehicle’s footprint, and the volume of vehicles the manufacturer actually produces.

Based on previous MY sales, NHTSA estimates that by MY 2025, passenger vehicles and light-duty trucks will need to meet an estimated combined average fuel economy of at least 48.7 to 49.7 miles per gallon. This estimate is subject to change based on the actual individual manufacturer fleet composition and production volumes. To view the annual standards, please refer to page 4 of the NHTSA CAFE Regulations for MY 2017 and Beyond fact sheet (

EPA GHG Emissions Standards

Similar to the NHTSA CAFE standards, the EPA also uses the footprint-based approach to determine carbon dioxide (CO2) emissions standards in grams per mile (g/mi) for each vehicle manufacturer. The EPA GHG emissions requirements are linked to the CAFE standards, and are also based on individual manufacturer fleet and production volumes. The EPA’s passenger car standards call for CO2 emissions reductions of 5% per year from MY 2017 to 2025. Light-duty trucks will have a bit more time to adjust to the standards, beginning with a 3.5% reduction per year from MY 2017 to MY 2021, then ramping up to a 5% reduction per year from MY 2022 to MY 2025. Refer to page 4 of the EPA GHG Emissions Standards for MY 2017-2025 fact sheet ( to see the projected CO2 emissions targets.


Manufacturers can meet these standards in a variety of ways. In addition to making direct improvements to vehicle components (e.g., engines and transmission efficiency, light-weighting), manufacturers may also achieve compliance by generating credits. First, manufacturers are required to calculate average fleet-wide tailpipe CO2 emissions and average fleet-wide fuel economy. These values serve as the baseline to which any additional earned credits can be added. The regulation also offers incentives to encourage advanced vehicle technologies.

These credits and incentives include:

  • Air Conditioning and Off-Cycle Improvements (EPA and NHTSA): Manufacturers can earn credits from efforts such as air conditioning efficiency improvements, as well as from off-cycle technologies that result in real-world benefits, like engine start-stop or solar panels on plug-in hybrid electric vehicles (PHEVs).
  • Advanced Technology Vehicles (EPA Only): The EPA regulation also includes incentives to encourage the production of advanced technology vehicles. For MYs 2017 to 2021, manufacturers that produce all-electric vehicles, PHEVs, compressed natural gas vehicles, and fuel cell electric vehicles may “count” these vehicles as more than one vehicle in their emissions compliance calculations.
  • Hybrid Electric Full-Size Pickups (EPA and NHTSA): Manufacturers are encouraged to produce a certain percentage of full-size pickup trucks that are hybrid electric vehicles, as they will receive compliance credits for doing so.

For more information on LDV GHG emissions and CAFE standards, please refer to the following resources:

Stay tuned for next month’s Question of the Month, where we will delve into the medium- and heavy-duty engine and vehicle standards.

Clean Cities Technical Response Service Team

EV Transportation and Technology Summit 2016

September 30, 2016 by Clean Cities

Hosted annually by the Electric Vehicle Transportation Center (EVTC) at UCF’s regional campus at the Florida Solar Energy Center in Cocoa, Fla., this year’s national Summit is focused on the transportation planning and infrastructure requirements accelerating the deployment of electric vehicles. Sixteen speakers will address current topics, including electric transit buses, wireless electric vehicle charging and the economics of electric vehicles. The speakers will also be looking to the future of transportation with presentations on planning for the next generation of innovative transportation and mobility. Speaker panel discussions, technical workshops and a poster session are also planned.

Registration, schedules, hotels and other information can be found at The last day for early registration and a special hotel rate is September 30th.

Summit sponsors include TECO Energy, Navigant Research, Proterra, OUC, Clipper Creek, NovaCharge, AutoPort, JEA, FPL, Drive Electric Florida and Central Florida Clean Cities.


About EVTC

The Electric Vehicle Transportation Center (EVTC) is a University Transportation Center funded by the U.S. Department of Transportation, and is the only center focused on electric vehicles. This research and education effort to help create the nation’s electric-vehicle transportation network is operated by the University of Central Florida’s Florida Solar Energy Center (FSEC) with partner universities, the University of Hawaii and Tuskegee University. The EVTC is bridging the gap between deployment of electric vehicles and the traditional transportation system. The EVTC researches and develops technologies, standards, planning and policies to ensure seamless integration of electric vehicles into a complex transportation network and supporting electricity grid. For more information, visit

About FSEC

The Florida Solar Energy Center, UCF’s energy research and education institute, was established in 1975. Located on the Cocoa campus of UCF and Eastern Florida State College, FSEC has gained national and international respect for its public and private partnerships, focusing on: solar energy, energy-efficient buildings, hydrogen and fuel cells, electric vehicles, smart-grid research, and testing and certification of solar equipment. The Center conducts continuing education and training programs for professionals, government and industry leaders around the world, in addition to Science, Technology, Engineering and Mathematics (STEM) opportunities for the future energy workforce. For more information, visit

America’s Partnership University

The University of Central Florida, the nation’s second-largest university with more than 60,000 students, has grown in size, quality, diversity and reputation in its first 50 years. Today, the university offers more than 200 degree programs at its main campus in Orlando and more than a dozen other locations. UCF is an economic engine attracting and supporting industries vital to the region’s future while providing students with real-world experiences that help them succeed after graduation. For more information, visit

What are the key considerations when installing ethanol equipment at a fueling station?

September 27, 2016 by Clean Cities

For those new to ethanol fueling, installing the necessary infrastructure may be unchartered territory. From fuel specifications to dispensing regulations, the recently updated Handbook for Handling, Storing, and Dispensing E85 and Other Ethanol-Gasoline Blends ( is the go-to source for all your ethanol station installation needs. The Handbook is designed for those who blend, distribute, store, sell, or use ethanol blends above E10 (90% gasoline blended with 10% ethanol). Below is a summary of some of the top infrastructure considerations:

Blend Level

If you are considering an ethanol fueling station, one of the first decisions to be made is the blend level. Specifically:

  • Low-level blend: E10

o   Regulations and Specifications: E10 is subject to the same regulations and specifications as regular gasoline.

o   Equipment: E10 can be stored and dispensed in existing gasoline fueling equipment.

o   Vehicle Applications: Any gasoline-powered vehicle

  • Mid-level blend: E15 (10.5% to 15% ethanol); other common offerings include E25 (25% ethanol) and E30 (30% ethanol)

o   Regulations and Specifications: ASTM International (ASTM) D4806 -Standard Specification for Denatured Fuel Ethanol for Blending with Gasoline for Use as Automotive Spark-Ignition Engine Fuel

o   Equipment: For underground equipment, stations must adhere to federal code, which requires compatibility. The majority of tanks and pipes are compatible with all ethanol blends. For above-ground equipment, stations must use equipment listed for the fuel being sold. A list of compatible equipment is available in the Handbook.

o   Vehicle Applications:

§  E15: Flexible fuel vehicles (FFVs), model year 2001 and newer conventional light-duty cars and trucks, and medium-duty passenger vehicles

§  E25 and E30: FFVs

§  Note: FFVs can operate on any blend of gasoline and ethanol, up to 83% ethanol.

  • High-level blend: E85 (51% to 83% ethanol, depending on geography and season), also called ethanol “flex fuel”

o   Regulations and Specifications: ASTM D5798 – Standard Specification for Ethanol Fuel Blends for Flexible-Fuel Automotive Spark-Ignition Engines

o   Equipment: E85 fueling equipment is subject to the same requirements as mid-level blend equipment.

o   Vehicle Applications: FFVs

Fuel Quality

Most transportation fuel sold in the United States is blended to ASTM specifications, the fuel quality standard. These standards are recognized by federal and most state government agencies as the primary means of ensuring fuel quality. Fleets and retailers should work with their fuel suppliers to confirm that the fuel provided meets these requirements. After the installation of ethanol fueling equipment, operational precautions, such as periodic checks (e.g., once every one to two months) of fuel properties, should be performed to help assure fuel quality.

Infrastructure Requirements

An ethanol station consists of approximately 60 interconnected pieces of fueling equipment necessary to deliver fuel to vehicles, including tanks, pipes, pump, dispenser, and hanging hardware. UL ( is the primary third-party safety certification labora­tory that has developed standards for listing fueling equipment.

As stated above, stations must meet federal compatibility requirements for underground equipment, which includes a letter stating compatibility from a manufacturer with specific biofuel blends or listing from a third party laboratory, such as UL. The majority of existing tanks and pipes are compatible with all ethanol blends. Some associated underground storage equipment, such as leak detection and prevention or fill equipment, may need to be replaced.

Above-ground equipment must be listed for the fuel blend being dispensed. UL listed above-ground equipment is available for E10, E25, and E85 blends. A complete list of compatible equipment is available in the appendices of the Handbook.

Note that some stations have UL-listed E85 blender pumps capable of legally dispensing ethanol blends between E0 and E85, including mid-level blends like E25 or E30, for FFV owners.


Federal law requires dispenser labels for ethanol blends above E10 to follow Federal Trade Commission specifications ( Labels must be placed on the front panel of the dispenser in a position that is clearly visible. Approved labels are available free of charge from the Blend Your Own website ( Some states have additional labeling requirements; check here to see if your state does:


When handling ethanol, it is important to keep safety procedures in mind. Like gasoline, ethanol is flammable, poisonous, and may contain addi­tives that can be harmful even with casual contact. To avoid risk, personal exposure to ethanol should be minimized. To fight an ethanol fire, specific equipment, materials, and training is required. Before offering blends above E10, consult your local fire marshal to determine regula­tions governing safe ethanol handling procedures. It is also important to be familiar with specifications detailed in the E85 material safety data sheet (

For additional information on installing ethanol equipment at a station, such as a full list of codes and regulations, as well as a checklist for installing and dispensing ethanol blends, refer to the Handbook.

In addition, check out the Alternative Fuels Data Center’s (AFDC) ethanol pages for general information, on ethanol fueling stations:

Clean Cities Technical Response Service Team


Central Florida Clean Cities Coalition 2016 Spring Recap

September 26, 2016 by Clean Cities

The Central Florida Clean Cities Coalition has been keeping busy, working to maintain its status as Central Florida’s leading alternative fuel technologies and vehicle advocates.  In February, Central Florida Clean Cities met virtually before a board at DOE headquarters comprised of Clean Cities Regional Managers, DOE labs personnel, and other program participants.  During this meeting, the coalition presented on its various alternative fuel and emissions reductions programs and partners, reaffirming its commitment to the Central Florida region with its many sustainability projects.  The Department of Energy has once again accepted our pledge, officially redesignating the coalition as a Clean Cities Coalition for the next three years.

The 2015 Clean Cities Annual Report was submitted in March and reflected the cumulative efforts of our Central Florida region, calculating the emissions reductions of Central Florida Clean Cities’ partner fleets.  In 2015, regional fleet managers report a cumulative 4,641,614 gallons of gasoline equivalent reductions, which means a GHG emissions reduction of almost 26,000 tons (a record high for Central Florida).  The majority of these reductions were achieved by local fleets adopting alternative fuel vehicles and infrastructure.  Congratulations, Clean Cities partners, and thank you for doing your part in enhancing transportation in our region.

Central Florida Clean Cities Coalition also did its part in attending various energy and alternative fuel vehicle conferences since the start of the year.  For instance, coalition representatives participated in the 2016 Energy Solutions Conference.  Held March 23-24, it was a sequel to the highly successful Virtual Conferences held in 2013 and 2012.  It was a Simulcast—a virtual event accessed by any computer or mobile device as well as in person at the Florida Solar Energy Center in Cocoa, FL.  The event featured presentations on energy options and choices, both now and in the future, with recognized experts from across the country speaking on topics such as renewable energy, energy efficiency, transportation planning, and more.  On Thursday, March 24, Central Florida Clean Cities Coalition Coordinator Colleen Kettles moderated a panel on Clean Cities and Alternative Fuel Vehicles, attended by representatives from various vehicle manufacturers, utilities, and clean cities stakeholders.  To learn more about this event, please visit the Energy Solutions Conference website at

Next, Drive Electric Florida (DEF) hosted its first 2016 meeting in Jacksonville on Monday, April 4 at the newly constructed North Florida Regional Transportation Management Center.  This state-of-the-art center opened last November, culminating a 12 year partnership between the North Florida TPO, the Florida Dept. of Transportation, and the Florida Highway Patrol to work towards safe and efficient travel in the Northeast Florida area.  The meeting featured speakers on industry updates, utility PEV updates, EV outreach events, and DEF committee reports.  This included a report on the newly formed Drive Electric Florida Workplace Charging (WPC) Committee, which first started meeting in early 2016.  Chaired by Peter King of Jacksonville Electric Authority and staffed by the Central Florida Clean Cities Coalition, the committee is in the process of pledging to be a Workplace Charging Challenge Ambassador, working on behalf of DOE to assist local businesses with WPC adoption.  To learn more about Drive Electric Florida or the Workplace Charging Challenge, please visit the DEF website:

Melbourne-Train-the-Trainer-2Central Florida Clean Cities then kicked off its First Responders Alternative Fuel Vehicle (AFV) Safety Training program in Melbourne on April 19.  This was the first of many “train the trainers” sessions, during which local first responder trainers are taught how to conduct workshops with their teams on approaching AFV collisions, particularly for propane, CNG/LNG, and electric vehicles.  This program will continue throughout the year with scheduled trainings pending in Tampa, Ocala, Broward County, and Jacksonville.

On April 20, intern Shauna Basques spoke on her year’s work with the Central Florida Clean Cities Coalition in the Clean Cities University Workforce Development Program’s end of semester presentation.  Busy staffing the Drive Electric Florida Workplace Charging Committee and assisting Coordinator Colleen Kettles with program projects and events, Shauna continued her work throughout the summer, advancing alternative fuel vehicle adoption.

2016-NASA_KSC-Earth-Day-EventCentral Florida Clean Cities also partnered with the Florida Solar Energy Center to present on energy efficiency, renewable energy, and alternative fuel vehicle solutions at the Kennedy Space Center/NASA’s Earth Day celebration, April 21 – 22.  On the event’s first day, presenters met with KSC/NASA personnel, displaying a Chevy Volt, a Nissan LEAF, and two solar ovens.  On the second day, these displays were moved into the Kennedy Space Center’s Visitor Complex, near the Rocket Garden, where presenters were able to meet with KSC visitors and staff alike, speaking on the benefits of AFVs and alternative energy sources.

EnergyWhiz took over the Florida Solar Energy Center in Cocoa, FL on Saturday, May 14.  Hundreds of students participated in renewable energy events, including a solar car sprint, an energy transfer machine competition, a solar energy cook-off, a display of EVs and the Electrathon.  For more information on the event, please visit

2016-Energy-Whiz-ElectrathonFinally, we attended the US DOE Clean Cities Southeast Regional Meeting in Jacksonville, May 18-20, 2016, where CFCCC Coordinator Colleen Kettles made a presentation on the FAST Act and its EV Corridor implications. On May 24, she traveled to NREL in Golden Colorado for a Clean Cities meeting on advanced technology vehicles and their impact on Clean Cities activities.

Although we’re done with spring, we’ll be reporting back on our summer events soon.  In the meantime, check out the upcoming 2016 EV Transportation and Technology Summit at  Hosted at the Florida Solar Energy Center in Cocoa, FL over October 17-20, the summit will feature presentations and industry panels on electric vehicle transportation planning, policy building, and future technologies designed to promote electric vehicle advancement.  Register now!

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