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Methodology

This tool provides a fuel cost comparison between a gasoline vehicle currently on the road and several replacement vehicle options: a newer gasoline vehicle, hybrid, plug-in hybrid, or battery electric vehicle.

The tool first estimates the cost to drive one mile in a typical gasoline vehicle in each ZIP code. That baseline cost is based on the fuel economy of gasoline vehicles registered in the area and local gasoline prices. The tool then compares that baseline with the cost to drive one mile in the selected replacement vehicle type.

The comparison is shown in two ways:

• Change in cost per mile: the difference between the current gasoline vehicle cost per mile and the replacement vehicle cost per mile.
• Change in cost per year: the cost-per-mile difference multiplied by the estimated annual miles driven.

For battery electric vehicles, the tool assumes that most charging occurs at home, with some charging at public stations, based on prior research on residential electric vehicle charging behavior. For plug-in hybrids, the tool assumes the vehicle is driven partly on electricity and partly on gasoline, using a 50% electric-driving share informed by real-world plug-in hybrid usage studies.

Annual mileage is estimated using household travel patterns and local demographic data. The estimates are developed at the census-tract level and then converted to ZIP-code-level values so they align with the tool’s fuel price and vehicle registration inputs.

Data Sources

1. Federal Highway Administration. 2017 National Household Travel Survey (NHTS). U.S. Department of Transportation.
2. U.S. Census Bureau. 2023 American Community Survey (ACS).
3. U.S. Department of Housing and Urban Development. USPS ZIP Code Crosswalk Files. https://www.huduser.gov/portal/datasets/usps_crosswalk.html
4. Experian, 2025 US LD EVD VIO. [Data Sets, available by subscription only]: Vehicle registration and model year distribution by ZIP code (2025 Q4 data).
5. Fueleconomy.gov. Plug-in electric vehicles fuel economy (2025 data).
6. GasBuddy: Gasoline prices by ZIP code (September 16, 2024, data, representing the 50th percentile of gasoline prices over the past five years.)
7. U.S. Energy Information Administration, residential electricity price data, April 2025.
8. AAA. Public EV Charging Price Data. Accessed May 23, 2025.
9. Blonsky, M., Munankarmi, P., & Balamurugan, S. (2021). Incorporating smart residential electric vehicle charging in home energy management systems. 2021 IEEE Green Technologies Conference (GreenTech), 187–194. IEEE. https://ieeexplore.ieee.org/document/9458480
10. Plötz, P., Moll, C., & Bieker, G. (2021). From lab-to-road: Real-world fuel consumption and CO2 emissions of plug-in hybrid electric vehicles. Environmental Research Letters, 16(5). https://iopscience.iop.org/article/10.1088/1748-9326/abef8c