Natural Gas
Light-duty natural gas internal combustion engine vehicles are typically dedicated natural gas or bifuel vehicles that use either natural gas or gasoline. The acceleration, horsepower, and cruise speed of natural gas vehicles and similar models of conventional vehicles are comparable, but natural gas vehicles generally have a shorter driving range because natural gas has a lower energy density (DOE, 2024). For additional background, see the Alternative Fuels Data Center's Natural Gas Vehicles webpage.
On this page, explore key cost and performance metrics for natural gas internal combustion engine vehicles, including modeled vehicle price, fuel economy, levelized cost of driving (LCOD), and emissions. Caveats for comparing powertrains are listed on the Light-Duty Vehicle Comparison page.
Vehicle Metrics: Fuel Economy and Modeled Vehicle Price
The following chart shows fuel economy and modeled vehicle price, metrics associated with the vehicle. Fuel economy represents how efficiently a vehicle converts fuel during operation. Modeled vehicle price represents an estimated cost to the consumer to purchase a new vehicle, based on modeling that includes manufacturing costs and profit.
The source of the 2024 Transportation Annual Technology Baseline (ATB) modeled vehicle price and fuel economy is the Argonne National Laboratory (ANL) report (Islam et al., 2023); the original data are available here. These data are developed using ANL's Autonomie simulation tool.
Select the data to display using the menus above the chart. Use the Metric filter to switch between fuel economy and vehicle cost data. Select the vehicle class, powertrain, and other powertrain details using the additional filters.
Vehicle and Fuel Metrics: Levelized Cost of Driving and CO2e Emissions
The following chart shows levelized cost of driving and CO2e emissions in addition to the associated fuel data. Levelized cost of driving is a metric that combines modeled vehicle price, fuel economy, fuel cost, and other assumptions for the selected fuel. CO2e emissions represents the emissions for the fuel well-to-wheels portion of the life cycle for the selected fuel. Emissions associated with vehicle life cycles are not included here.
These calculations use data from Argonne National Laboratory, which develops and applies the Autonomie simulation tool and R&D GREET model (Wang et al., 2023). Links to data from the ANL report (Islam et al., 2023) on modeled vehicle price and fuel economy are available here.
Select the data to display using the buttons and menus above the chart. Use the Metric filter to switch between LCOD and CO2e emissions data. Select the pathway, scenario, vehicle class, and powertrain details using the additional filters. Clicking the black arrows on the top right of the figure shows additional details of the selected fuel pathways. The underlying source for a data point in the chart can be seen by placing your mouse cursor over that data point. The data sources are also cited—with linked references—in the Key Assumptions section next.
Notes:
- The levelized cost of driving in the ATB includes vehicle, fuel, and maintenance costs. See the levelized cost of driving definition for details of what is included in and excluded from LCOD in the ATB.
- Changes over time are attributable only to projected vehicle cost and performance; the fuel cost and emissions are constant over time.
- The Fuel Pathway filter displays the selected fuel pathways for the Baseline Fuel, Lowest Cost Fuel, and Lowest CO2e Emissions Fuel. The full set of fuel pathways is available in the data download.
- Emissions references and fuels costs and prices references do not always use the same data source for a given pathway. We recommend caution in interpretation of combined sources of information.
Key Assumptions
The data and estimates presented here are based on the following key assumptions:
- Fuel Economy Improvements: The assumptions about fuel economy improvements reflect the adoption of lightweighting and engine efficiency technologies consistently across vehicle powertrains for a given trajectory; they do not account for the trade-offs between efficiency and performance in various vehicle markets. The cost and fuel economy trajectories are based on the analysis year Autonomie modeling results for the conventional compressed natural gas powertrain from Islam et al. (Islam et al., 2023). The ATB Advanced trajectory corresponds to the Base performance, High technology progress case. The ATB Mid trajectory corresponds to the Base performance, Low technology progress case. The ATB Conservative trajectory is based on the Annual Energy Outlook (EIA, 2023).
- High Production Volume: The estimates from Islam et al. (Islam et al., 2023), and those shown here, represent costs and technology performance at high production volume. Because internal combustion engines are currently manufactured at high volume, we do not apply low production volume cost multipliers to natural gas vehicles and thus ignore the lower production scale of natural gas fuel tanks.
- Vehicle Variations: The Transportation ATB presents estimates for a representative light-duty vehicle; we do not account for variations in make, model, and trim or for pricing incentives or geographic heterogeneity that influence prices in the market. As a result, representative values shown here may differ from specific models available on the market.
- Natural Gas Fuel Tank Cost Advancements: Advancements in natural gas fuel tank costs contribute to the total cost reductions seen in natural gas internal combustion engine vehicles. Based on Islam et al. (Islam et al., 2023) and (Wang et al., 2023), fuel tank manufacturing costs decrease by $2,500 and $3,400 in the Mid and Advanced trajectories, respectively (which correspond to $3,700 and $5,100 decreases in the purchase cost equivalent shown in the charts above). Fuel tank cost reductions are based on technology advancements but also on improved efficiency requiring lower fuel tank volume.
- Technology Advances: Technology advances include changes that may reduce costs or may increase costs while improving performance, which implies costs do not always decline between less- and more-advanced scenarios.
- Nonmonotonic Behavior: Modeled vehicle price trajectories may exhibit nonmonotonic behavior resulting from the combination of advanced technology costs and the impact on engine efficiency. For example, though the engine cost might increase over time because of advanced technologies, the overall engine power required decreases over time because of lightweighting, improved aerodynamics, or other factors. As a result, though per unit of power engine costs might go up, lower engine power requirements decrease the total engine cost.
- Baseline Fuel Pathway: The baseline fuel pathway used for this powertrain in the LCOD and emissions estimates is natural gas (market).
- Frozen Fuel Price Level: The fuel price and emissions of the selected fuel pathways (e.g., Baseline, Lowest Cost, and Lowest Emissions) are associated with a single year. Because we do not provide a time-series trajectory, here we show fuel price at a frozen level for all years so we can offer a range of fuel price values. In the levelized cost of driving and emissions charts, this approach clearly distinguishes the effects of fuels from those of vehicle technologies because fuels remain constant whereas vehicle technologies change over time.
- Fuels References: See fuels pages, especially natural gas, for a full description of fuels references, which include (DOE, 2023) and (Wang et al., 2023).
- Fuel Economy on Substitutable Fuels: The Transportation ATB assumes the fuel economy (on a miles per gallon gasoline equivalent basis) remains constant when operating on substitutable fuels (e.g., conventional E10 gasoline versus reformulated E15 gasoline). In reality, fuel composition may affect engine performance.
The data downloads include additional details of assumptions and calculations for each metric.
Definitions
For detailed definitions, see:
References
The following references are specific to this page; for all references in this ATB, see References.