Comparing annual fuel costs for electric vs gasoline vehicles.
By Jed Bailey | December 18, 2018
Our previous report examined the relative cost per mile to fuel electric vehicles (EVs) and internal combustion engine (ICE) vehicles. Relative electricity and gasoline prices are the only variable that affect the attractiveness of each technology – drivers in each state also have distinct driving habits, including the total distance driven each year and the balance between city and highway driving.
This third report in our series on EVs and ICEs examines the impact of state-level differences in the estimated annual vehicle miles driven, on the relative fuel costs for EVs and ICEs. In this analysis, we apply the results from our previous report to calculate the total annual fuel costs to drive a Chevy Bolt or a Chevy Cruze in 2016, based on the average annual miles driven per state.
Like electricity and gasoline prices, there is a wide range in the average annual miles driven per vehicle in each state. While data is not directly available for miles driven per vehicle at the state level, the Federal Highway Administration does calculate total vehicle miles per state. We combined this data with the reported number of registered drivers per state to estimate the miles driven per vehicle by state (see Figure 1 below). Note that this approach assumes that all reported vehicle miles in a state are driven by drivers registered in that state.
Based on this methodology, the calculated annual miles per registered driver for most states lie within a relatively tight band around the national average of just over 14,300 miles per year. Notable outliers include the District of Columbia (7,400) and Arizona (7,000) on the lower end, and Missouri (36,700) on the higher end.
Multiplying the annual miles driven by the vehicle’s fuel cost per mile calculated in our previous report results in the total annual fuel cost for the vehicle’s owner in each state (assuming it is the only car that they drive). Figure 2 below compares the 2016 annual fuel cost for the Chevy Cruze and Chevy Bolt by state.
Adding in the state-level data on miles driven changes the relative standings dramatically. Here Missouri is shown to be the state with the highest annual fuel cost for both vehicles owing to the high annual mileage. It is also the state with the greatest difference in fuel costs for the two vehicles, with the Cruze (ICE) requiring more than US$1,000 more to fuel than the Bolt (EV). By contrast, the relatively low annual mileage in Hawaii keeps annual fuel costs to less than US$1,000 for both technologies despite having the highest fuel cost per mile. Arizona’s combination of moderate fuel and electricity costs and low annual mileage make it the state with the lowest overall fuel bill.
The chart also highlights the wide range in annual fuel expenditures across the states. For ICE’s like the Cruze, a driver’s annual fuel bill can range from roughly US$500 per year to nearly US$2,200. This 4x spread between the highest and lowest annual fuel spend is much wider than the 50% spread between the states with the highest and lowest gasoline prices shown in our previous report.
Indeed, the states with the highest and lowest gasoline prices (Alaska and Texas) are not the states with the highest and lowest annual fuel spend (Missouri and Arizona). The same is true of EVs, with the driver’s annual fuel bill ranging from just over US$200 to nearly US$1,200 depending on the state. As with ICEs, the 6x spread in annual fuel cost for EVs is much wider than the 3x spread in residential electricity tariffs. Here again, the states with the highest and lowest electricity tariffs (Hawaii and Louisiana) are not the same states with the highest and lowest annual fuel spend (Missouri and Arizona).
This wide range in total costs affects the average savings in fuel spend that comes from switching to an EV. In Missouri, switching from a Cruze to a Bolt would cut fuel costs by $1,000 per year—a 47% reduction. A Washington driver that switched would cut their fuel costs by 67%–the highest percent reduction—but would save only $500 per year. In Hawaii, where both vehicles are expensive to fuel, switching to the EV would cut fuel costs by just 10%, saving around $95 per year.
While drivers in states with higher fuel cost savings are most likely to reap the benefits of switching from an ICE to an EV, the difference in the purchase price of each vehicle (including any state or federal tax incentives or subsidies) must also be factored in to calculate the total cost to own each in each state.
Previous reports in this series include:
A description of the graphical methodology comparing EVs and ICEs fuel costs.
An analysis of the state-level fuel cost per mile for EVs and ICEs.
Our next report in this series will compare how different driving habits affect the fuel costs for the same two cars. A fifth report will then consider differences in vehicle fuel economy across different EV and ICE models..
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