Hybrid vehicles - The Sustainability Management Wiki

Authors: Andres Cristancho, Leonardo Nazareno
Edited by: –
Last updated: May 18, 2026

Executive summary

Hybrid vehicles combine an internal combustion engine with an electric motor to reduce fuel use and emissions while preserving driving range and performance. They have existed in concept for more than a century, but modern hybrids gained traction in the 1990s and became mainstream after the success of the Toyota Prius. Today, many manufacturers offer hybrid models, and regional strategies vary, with gasoline-electric hybrids prevalent in the United States and Japan and greater emphasis on mild diesel hybrids in parts of Europe.

Hybrids can deliver meaningful efficiency gains through regenerative braking, stop/start operation, and electric assist, and they can be categorized by hybridization level (micro, mild, full, and plug-in) and by powertrain architecture (series, parallel, and power-split). These design choices influence how much the vehicle can rely on electric driving, how efficiently the engine operates, and the overall complexity and cost of the system.

From an economic perspective, hybrids have become increasingly competitive. Technology learning has reduced costs, and rising prices for conventional vehicles have narrowed the cost gap. In several markets, total cost of ownership studies show hybrids can be close to, or better than, comparable internal combustion and battery electric options once fuel/energy, maintenance, depreciation, and other ownership costs are included. Regulatory pressure on fleet-average emissions further encourages manufacturers to expand hybrid offerings.

Ecologically, hybrids generally reduce greenhouse gas emissions and local air pollutants compared with conventional vehicles, especially in urban driving where regenerative braking and electric-only operation can be used more often. However, life-cycle impacts matter: battery production, the electricity mix for charging (for plug-in hybrids), and end-of-life treatment can affect overall environmental performance. Over typical use, operational savings can offset higher manufacturing impacts.

Social impacts include potential improvements in urban air quality and reduced noise, which can benefit public health and livability. Adoption patterns vary by consumer segment and geography, influenced by environmental attitudes, fuel prices, incentives, and the availability of supporting infrastructure. Policy design remains crucial: consistent standards and well-targeted incentives can accelerate emissions reductions, while shifting priorities toward zero-emission vehicles can reduce support for hybrids. Overall, hybrids can serve as a pragmatic bridge technology for organizations and individuals seeking near-term emissions reductions without major operational disruption.

1 Description and history

The transport sector supports everyday life by enabling trips to work, school, and essential services. It also consumes significant energy: it accounts for about 26% of global final energy consumption and has substantial potential to improve toward the 2030 NZE target, which requires roughly a 5% annual improvement in global final energy intensity.¹

As organizations and consumers prioritize lower-emission mobility, demand for environmentally friendly vehicles continues to grow. Fully electric vehicles remain the long-term solution, but limited driving range and other practical constraints still affect market acceptance. Hybrid vehicles therefore play a meaningful transitional role by reducing fossil fuel use without sacrificing range or power.

Hybrid vehicles use more than one energy source. The most common configuration pairs an internal combustion engine (ICE) with an electric motor. Many models use the ICE for higher-speed or longer-distance driving and rely more on the electric motor at lower speeds and for shorter trips.²

Battery performance remains the main constraint on the electric component. Current battery energy density is still lower than liquid fuels, which limits range, and battery costs remain high.³

Hybrid technology is not new. In 1900, Ferdinand Porsche developed an early gasoline-electric hybrid concept. Later, the Lohner-Porsche Mixte Hybrid (released in the 1920s) demonstrated key advantages by combining an electric motor powered by batteries with a gasoline engine that could recharge the batteries or provide additional power. Researchers continued to explore hybrid designs in the 1930s and 1940s, and models such as the Woods Dual Power helped popularize the concept through commercial availability. During the 1960s and 1970s, however, most major manufacturers focused on improving the efficiency of conventional internal combustion vehicles.⁴

Interest returned in the 1990s, driven by oil-price concerns, advances in battery technology, and growing global awareness of environmental impacts. The 1997 Toyota Prius became a major milestone. Its commercial success established hybrids as a viable eco-friendly option and encouraged broader adoption across the automotive sector.⁴

Today, manufacturers such as Volkswagen, BMW, Honda, BYD, and Nissan invest heavily in hybrid research and development. Regional priorities differ: gasoline-electric hybrids dominate in the United States and Japan, while Europe places greater emphasis on mild diesel hybrid technology.³

Analysts commonly classify hybrid vehicles by (1) hybridization rate (Table 1) and (2) powertrain configuration (Table 2).⁵

Function or Component Parameters Types of Hybrid Electric Vehicle
Micro Mild Full Plug-In
Hybridization Level <5% 50% >50%
Increment in Fuel Efficiency 5-10% 20-25% 40-45% Not Defined
Battery Voltage (V) 12 48-160 200-300 300-400
Electric Machine Power (kW) 2-3 10-15 30-50 60-100
EV Mode Range (km) 0 0 5-10 >10
CO₂ Estimated Benefit 5-6% 7-12% 15-20% >20%
Idle Stop/Start ♦ ♦ ♦ ♦
Electric Torque Assistance ♦ ♦ ♦
Energy Recuperation ♦ ♦ ♦
Electric Drive ♦ ♦
Battery Charging ♦ ♦
Battery Charging (For Grid) ♦

Table 1: Comparison of micro, mild, full and plug-in hybrids

When classifying by powertrain configuration (Table 2), series hybrids use the internal combustion engine to generate electricity, which then powers the electric motor that drives the drivetrain. In parallel hybrids, both the ICE and the electric motor connect to the drivetrain and operate under different conditions. In many parallel designs, the ICE provides primary traction while the electric motor assists, but these systems can be less suitable for typical stop-and-go city driving because frequent changes can drain the battery.

Power-split hybrids use a planetary gear set to divide engine power into mechanical and electrical paths. This design helps the engine operate closer to its most efficient range while the electric motor assists propulsion and recovers energy. By combining key advantages of series and parallel systems, power-split architectures improve efficiency and flexibility, but they also require more complex designs, advanced control, and higher costs.⁵

Table 2: Power-train configuration

Most hybrid vehicles use several enabling technologies. Regenerative braking captures energy that would otherwise be lost during braking and uses it to recharge the battery. Automatic stop/start systems shut off the engine when the vehicle stops and restart it when the driver accelerates. Finally, an electric drive or assist motor supports the ICE during peak power demand, which enables smaller, more efficient engines.⁵

2 Economic performance

Hybrid vehicles have gained market acceptance in recent years because they balance performance with lower emissions. In the United States, their share of total annual light-duty vehicle sales reportedly increased from 2% in 2015 to 12% in 2025 (Wards Intelligence data). Growth has been strongest in the non-luxury segment, where the hybrid share rose from 2% to 14% over the past decade. In the luxury segment, hybrids also grew, but battery electric vehicles still dominate among alternative powertrains.⁶

Two factors largely explain the rise in competitiveness. Technological learning has improved performance while reducing costs, and conventional vehicle prices have increased, which reduces the price gap as a deciding factor. For example, in Germany, the overall price of electric and plug-in hybrid vehicles declined substantially after mass-market introduction in 2010. Over a six-year period, the specific real price of plug-in hybrids decreased from 320 to 260 €/kW, while conventional vehicles increased from 180 to 220 €/kW.⁷

The smaller cost difference between technologies, growing interest in sustainable lifestyles, and government policies have all supported higher adoption. In Indonesia, studies comparing the Honda HR-V E CVT (internal combustion), the BYD Dolphin (electric), and the Toyota Yaris Cross (hybrid) show that the total cost of ownership differs by only about 3% between the least expensive and most expensive option when accounting for purchase price, taxes, maintenance, energy, depreciation, and insurance. This indicates that hybrids can compete closely with other technologies in some markets.

In the United States, one comparative study found that the internal combustion vehicle had the lowest initial purchase price, but the highest total cost of ownership after 120,000 miles. In that analysis, the hybrid was the most economical option in 2016 (Table 3).⁸

ICEV HEV EV
Retail Cost $27.130 $27.642 $31.590
Fuel Cost $11.024 $5.053 $3.367
Operation Cost $24.497 $21.820 $23.840
Total Cost of Ownership $62.651 $54.515 $58.797

Table 3: Total cost of ownership in 2015 (USD)

Regulations have also influenced manufacturer strategies. Vehicle-fleet emission limits push companies to reduce average emissions to avoid major penalties (for example, EU Regulation 2019/631). Toyota has remained among the best positioned on average emissions and has sustained strong hybrid sales. Other manufacturers that have achieved comparatively low averages include PSA Group, Suzuki, and Hyundai-Kia. Similar patterns appear in the United States, where the Toyota Prius led the market for many years; although competition has increased, hybrids remain well established in the sector.⁹

Using cost increases in euros as a benchmark, studies suggest that electric and hybrid vehicle costs tend to decline over time, while internal combustion vehicle costs can rise due to weight-reduction requirements. In addition, hybrids showed the lowest cost increase among emission-reduction-focused technologies in one assessment. While projections indicate that hybrid prices may decline more slowly than fully electric vehicles, they are expected to remain competitive through 2030. This approach considers cost changes in major components such as batteries, engines, transmissions, and electrical systems.¹⁰

Overall, these studies indicate that hybrid vehicles can be economically competitive, although results vary by country and policy context. The broader trend points to increasing acceptance among users who want to reduce emissions without major compromises in usability.

3 Ecological performance

The transportation sector accounted for a substantial share of emissions in 2019 and is projected to grow significantly by mid-century.¹¹

Replacing fossil fuels (petrol, diesel, and gas) with electricity can reduce greenhouse gas emissions in transportation. Electric vehicles can offer larger reductions (around 90%) than hybrid electric vehicles, which often achieve reductions of about 25% relative to conventional vehicles.¹²

Life-cycle impacts complicate the comparison. Battery manufacturing, the electricity mix used for charging, and end-of-life treatment can increase environmental impacts if stakeholders do not manage them carefully.¹³

To evaluate the ecological performance of hybrid electric vehicles (HEVs), it helps to consider emissions across the full vehicle life cycle and compare them with other transport options. Figure 1 summarizes an automotive supply chain with four stages: (1) vehicle manufacturing (forward supply chain), (2) energy supply for manufacturing and vehicle operation, (3) vehicle use, and (4) end-of-life and recycling activities (reverse supply chain), including the recycling of dismantled components and the handling of manufacturing waste.¹⁴

Figure 1: Structure of the automotive industry supply chain.¹⁴

HEVs can improve air quality by reducing tailpipe emissions of pollutants such as NOx and particulate matter, which can lower the incidence of respiratory disease and other health effects associated with poor air quality.¹⁵

Stop-start operation contributes to these benefits by avoiding idling emissions in congestion, school zones, and other locations where stationary vehicles can create localized pollution.¹⁶

Table 4 summarizes emissions for internal combustion vehicles (ICEV), HEVs, and EVs.

ICEV HEV EV
CO₂ 613.5 319.4 384.0
CH4 0.926 0.577 0.736
N2O 0.021 0.017 0.007
VOC 1.085 0.974 0.094
CO 7.871 7.810 0.445
NOx 0.983 0.832 0.452
PM10 0.191 0.151 0.550
SOx 0.404 0.380 1.079
GHGs 642.6 338.7 404.1

Table 4: Total emissions per vehicle type in grams per mile shown by pollutant component and in aggregated form. Carbon dioxide (CO₂), methane (CH4 ), nitrous oxide(N2O), volatile organic compound (VOC), carbon monoxide (CO), nitrogen oxides (NOx), particle matter with diameter less than 10 µm (PM10), sulphur oxides (SOx).⁸

In this comparison, HEVs show the lowest aggregate greenhouse gas emissions, at about 339 grams per mile, which is roughly half the emissions of the ICEV.⁸

For ICEVs, most greenhouse gas emissions occur during the use phase. For HEVs and EVs, manufacturing—especially battery production—contributes a larger share of life-cycle emissions through the production and use of metals, chemicals, and energy.¹⁷

For example, lithium-ion battery materials and production can account for 2–5% of plug-in hybrid vehicle life-cycle emissions.¹⁸

Externality costs also vary by technology. In one assessment, greenhouse gas costs accounted for 21% of externalities in HEVs (the lowest share) and 32% in ICEVs (the highest share). Hybridization can therefore reduce costs in the short term because the technology already exists and does not require new fueling infrastructure.⁸

Overall, EVs show the lowest total externalities cost in that same study.

ICEV HEV EV
GHGs 1,899 1,003 1,195
Air quality 2,619 2,541 1,883
Time cost 1,482 1,152 899
Total externalities cost 6,001 4,696 3,978

Table 5: Externalities cost in 2015$. Estimations are based on vehicle lifetime of 10.6 years and annual mileage of 11,300.⁸

Driving behavior affects hybrid fuel efficiency. High speeds and aggressive acceleration increase fuel consumption, while steady driving at optimal speeds improves efficiency.¹⁵

Battery performance also matters. Newer lithium-ion batteries can provide higher energy density and longer driving ranges than older nickel-metal hydride batteries.¹⁵

Pairing batteries with an ultracapacitor (UC) can extend battery life and improve charge/discharge rates by reducing internal resistance and heat losses; some analyses report an efficiency-cycle increase from 80% to 90%.¹⁵

HEVs typically perform best in urban conditions because they can use electric-only operation and regenerative braking more often.¹⁶

In these conditions, the electric motor can operate for about 30–57% of the time.¹⁹

Battery electric vehicles (BEVs) can deliver stronger environmental performance in urban operation. However, plug-in hybrids can outperform BEVs in motorway driving and some mixed driving cycles. Because HEVs and PHEVs adapt across operating conditions, they can bridge the transition from ICEVs to full electrification by reducing emissions without requiring abrupt changes to fleets or infrastructure.²⁰

Table 6 highlights typical life-cycle improvements of HEVs over ICEVs. HEVs can require more manufacturing energy because they include additional components, especially battery systems and rare earth materials. In many cases, operational benefits offset these drawbacks within 6–12 months of normal use.¹⁶

Environmental Impact Category ICEV HEV Improvement
Lifecycle CO₂ (tons/vehicle) 58.5 43.2 26% reduction
Manufacturing Energy (GJ) 85 105 24% increased
Operational Energy (GJ/year) 45 32 29% reduction
Water Consumption (liters) 58,000 52,000 10% reduction
Criteria Pollutants (kg) 12.5 7.8 38% reduction

Table 6: Lifecycle environmental impact comparison between ICEV and HEV¹⁶

Future environmental impacts of HEVs will depend on continued technological progress, market penetration, and integration with broader sustainable energy systems.¹⁶

4 Social impact

HEVs can create social benefits for drivers, passengers, and communities, particularly through lower noise and reduced pollution.¹⁵

Air pollution from ICEVs creates significant public-health risks, contributing to respiratory and cardiovascular disease and to premature mortality globally.²¹

One study reported that, under average weather conditions, replacing all ICE passenger vehicles with HEVs could prevent 84.1 deaths due to long-term reductions in PM10 concentrations.²²

Vehicle engines also contribute to noise, especially during acceleration.¹⁵

Because electric drivetrains produce less mechanical noise, HEVs and EVs can reduce urban noise pollution as adoption increases. This change can improve city noise maps, which visualize noise exposure in specific areas and support planning and assessment.²³

Market reception varies by consumer segment and geography. Early hybrid buyers typically reported higher environmental awareness, stronger technology acceptance, and higher disposable income than ICEV buyers. Adoption rates have tended to be higher in areas with elevated fuel prices, stronger environmental awareness, heavy traffic congestion, and supportive incentives.¹⁶

Early surveys also found that some households associated hybrid ownership with being informed and environmentally aware, and they viewed the vehicles as advanced technology.²⁴

Gasoline prices have also influenced adoption. Even relatively small changes in fuel prices can shift purchasing patterns among people shopping for a new vehicle, as consumers reconsider fuel savings and fuel economy.²⁵

As markets matured, hybrids expanded beyond early adopters to mainstream buyers seeking fuel savings and lower emissions. However, ICEVs still dominate in many markets because they have lower upfront costs, broader model availability, and strong consumer familiarity.

Infrastructure and compatibility also shape adoption. ICEVs benefit from well-established fueling infrastructure and familiar refueling procedures. HEVs can use the same infrastructure while also offering plug-in charging for plug-in hybrids, which increases operational flexibility and can reduce range anxiety compared with fully electric vehicles.

Looking ahead, regulatory requirements, consumer acceptance, and ongoing technology improvements will likely continue to support hybrid adoption across segments and regions. Clear communication of benefits—fuel economy, emissions reductions, and total cost of ownership—can further accelerate uptake, especially as manufacturers integrate hybrid systems across more vehicle platforms.¹⁶

5 Political and legal aspects

Political and legal frameworks strongly influence the adoption of hybrid technology. Although international efforts aim to align countries toward shared climate and air-quality goals, national sovereignty often leads to different policy mixes. Many policies apply to both electric and hybrid vehicles. Key examples include fleet-average CO₂ emission limits (measured in g CO₂/km), which are common in Europe, and demand-side incentives such as purchase subsidies, tax relief over multiple years, or non-monetary benefits such as access to priority lanes or preferential parking.²⁶

Policy direction can change when governments change. As a result, country-specific analysis often provides a more realistic view than global generalization. In Europe, Regulation (EU) 2019/631 sets CO₂ emission standards for new vehicles. Although the regulation has been amended over time (with the latest officially published on 19.6.2025), its core aim has remained to motivate manufacturers to provide more sustainable alternatives.²⁷

Europe has also adopted measurement methods intended to better reflect real-world driving, such as the Worldwide Harmonized Light Vehicle Test Procedure (WLTP). WLTP was expected to address shortcomings of earlier test cycles and to improve the precision of CO₂ emission quantification by 25%.²⁸

At the same time, since 2023, subsidy policies have increasingly prioritized zero-emission vehicles rather than hybrids. As one example, plug-in vehicle sales reportedly fell from a 40% share of new electric vehicle sales in 2022 to 33% in 2024.²⁹ This shift signals a stronger policy emphasis on full electrification as a pathway to NZE2030.

The United States illustrates how policy can change across administrations. Under President George W. Bush, the federal government funded hybrid research and offered tax relief to buyers beginning in 2005. Later, President Obama reinforced support and further increased sales. Under the Trump administration, incentives existed initially but then declined over time. President Biden sought to re-expand support, including higher subsidy values³⁰, but after Trump returned to office, policy again became less supportive of this technology. For example, in March 2025, 8 of the 15 states that offered incentives reduced their tax benefits.²⁹

Overall, hybrids can serve as a transitional technology, but their impact depends on political choices. Strong, well-designed policies can accelerate emission reductions, while weak or inconsistent support can slow progress toward full electrification.³¹

Asia includes major automotive producers in China, Japan, and South Korea. In China, the government implemented subsidies for hybrid vehicles in 2009–2010. Starting in 2017, it gradually replaced subsidies with the “Double Points” policy, which pushes manufacturers to reduce average fuel consumption and increase production of new energy vehicles.³⁰

Although hybrid market share has increased recently and can reach cost levels comparable to internal combustion vehicles.²⁹, the share may decline in coming years as the policy focus shifts toward fully electric vehicles. In Japan, a “green tax system” introduced in 2009 reduced taxes for low-emission vehicles. Japan also made large state investments in 2012 and created an “all-Japan system” to support collaboration on batteries and key components. While both China and Japan used subsidies and fiscal incentives to boost adoption, China relied more on direct regulatory intervention, whereas Japan emphasized industry–academia cooperation to accelerate technology development.³⁰

In South America, Brazil has significant potential due to its automotive industry (more than 5 million units per year capacity as of 2020) and a power system that reportedly generates 72% of electricity from renewable sources (54% hydro, 12% wind, and 6% PV).³² However, some assessments estimate that the investment payback period can be 55% longer than in European countries due to high taxes, insurance costs, and limited policy support.³³

Despite these barriers, studies that compare a Business-as-Usual scenario and the Brazilian Ministry of Mines and Energy’s National Energy Plan projection suggest that hybrids could dominate the fleet. Under the BAU scenario, hybrids could represent 55% of the fleet, while under the government’s proposed scenario they could reach 85% by 2050.³⁴

Several South American countries may also benefit from higher shares of renewable electricity for charging and from biofuel potential. However, limited charging infrastructure outside major cities can make hybrids an important contributor in near-term transition pathways.

References

1
Agency, I. E. Energy Efficiency 2023. (IEA, Paris, 2023).
2
Talari, K. & Jatrothu, V. A Review on Hybrid Electrical Vehicles. Strojnícky časopis – Journal of Mechanical Engineering 72, 131-138 (2022). https://doi.org:10.2478/scjme-2022-0023
3
Yao, S. et al. 1237-1247 (2025).
4
Ikpe, A., Bassey, M. & Akpan, I. A Systematic Review of Hybrid Electric Vehicle Technologies and Their Impacts on Environmental Sustainability. Information Sciences and Technological Innovations 2, 1-23 (2025). https://doi.org:10.48314/isti.v2i1.28
5
Pan, Y. et al. A Review of Hybrid Vehicles Classification and Their Energy Management Strategies: An Exploration of the Advantages of Genetic Algorithms. Algorithms 18, 354 (2025).
6
Administration, U. S. E. I. Hybrid vehicle sales continue to rise as electric and plug-in vehicle shares remain flat, (2025).
7
Weiss, M., Zerfass, A. & Helmers, E. Fully electric and plug-in hybrid cars – An analysis of learning rates, user costs, and costs for mitigating CO₂ and air pollutant emissions. Journal of Cleaner Production 212, 1478-1489 (2019). https://doi.org:https://doi.org/10.1016/j.jclepro.2018.12.019
8
Lambros K. Mitropoulos, P. D. P., Pantelis Kopelias. Total cost of ownership and externalities of conventional, hybrid and electric vehicle. Transportation Research Procedia 24, 267-274 (2017).
9
Energy, U. S. D. o. U.S. HEV Sales by Model, (2025).
10
Wolfram, P. & Lutsey, N. Electric vehicles: Literature review of technology costs and carbon emissions. (2016).
11
Ferrer, A. L. C. & Thomé, A. M. T. Carbon Emissions in Transportation: A Synthesis Framework. Sustainability 15, 8475 (2023).
12
Singh, K. V., Bansal, H.O. & Singh, D. A comprehensive review on hybrid electric vehicles: architectures and components. Journal of Modern Transportation 27, 77-107 (2019).
13
Shrey Verma, G. D., Puneet Verma. Life cycle assessment of electric vehicles in comparison to combustion engine vehicles: A review. Materials Today: Proceedings 49, 217-222 (2022).
14
H.-O. Günther, M. K., N. Autenrieb. The role of electric vehicles for supply chain sustainability in the automotive industry. Journal of Cleaner Production 90, 220-233 (2015).
15
Ikpe, A., Bassey , M. ., & Akpan , I. A Systematic Review of Hybrid Electric Vehicle Technologies and Their Impacts on Environmental Sustainability. Information Sciences and Technological Innovations 2(1), 1-23 (2025).
16
Kumbar, P. Impact of Hybrid Vehicles on Fuel Economy and Emissions: A Comprehensive Analysis. World Journal of Advanced Research and Reviews 08(01), 307-319 (2020).
17
Carla Tagliaferri, S. E., Federica Acconcia, Teresa Domenech, Paul Ekins, Diego Barletta, Paola Lettieri. Life cycle assessment of future electric and hybrid vehicles: A cradle-to-grave systems engineering approach. Chemical Engineering Research and Design 112, 298-309 (2016).
18
Das, P. K., Bhat, M.Y. & Sajith, S. Life cycle assessment of electric vehicles: a systematic review of literature. Environmental Science and Pollution Research 31, 73-89 (2024).
19
P Lijewski, A. Z., P Daszkiewicz, M Andrzejewski and D Gallas. Comparison of CO₂ emissions and fuel consumption of a hybrid vehicle and a vehicle with a direct gasoline injection engine. IOP Conference Series: Materials Science and Engineering 421 (2018).
20
Laene Oliveira Soares, J. R. S., Ronney Arismel Mancebo Boloy. Lifecycle assessment and environmental impacts of hybrid electric vehicles fuelled by bioethanol and biogas. Renewable and Sustainable Energy Reviews 216 (2025).
21
Hartmann, P., Apaolaza, V., Eletxigerra, A., Barrutia, Jose M. & Echebarria, C. Beyond Climate Change Concern: Why Air Pollution Health Concern and Health Orientation Matter in Battery Electric Vehicle Adoption. Business Strategy and the Environment 34, 8020-8033 (2025). https://doi.org:https://doi.org/10.1002/bse.70003
22
Maesano, C. N. et al. Impacts on human mortality due to reductions in PM10 concentrations through different traffic scenarios in Paris, France. Science of The Total Environment 698, 134257 (2020). https://doi.org:https://doi.org/10.1016/j.scitotenv.2019.134257
23
Campello-Vicente, H., Peral-Orts, R., Campillo-Davo, N. & Velasco-Sanchez, E. The effect of electric vehicles on urban noise maps. Applied Acoustics 116, 59-64 (2017). https://doi.org:https://doi.org/10.1016/j.apacoust.2016.09.018
24
Heffner, R., Kurani, K. S, & Turrentine, T. S. Symbolism In Early Markets For Hybrid Electric Vehicles. (UC Davis: Institute of Transportation Studies, 2007).
25
Diamond, D. The impact of government incentives for hybrid-electric vehicles: Evidence from US states. Energy Policy 37, 972-983 (2009). https://doi.org:https://doi.org/10.1016/j.enpol.2008.09.094
26
Stephens, T., Zhou, Y., Burnham, A. & Wang, M. Incentivizing Adoption of Plug-in Electric Vehicles: A Review of Global Policies and Markets. (United States, 2018).
27
European Parliament & European Council. Official Journal of the European Union (2019).
28
Pavlovic, J., Ciuffo, B., Fontaras, G., Valverde, V. & Marotta, A. How much difference in type-approval CO₂ emissions from passenger cars in Europe can be expected from changing to the new test procedure (NEDC vs. WLTP)? Transportation Research Part A: Policy and Practice 111, 136-147 (2018). https://doi.org:https://doi.org/10.1016/j.tra.2018.02.002
29
Transportation, I. C. o. C. Plug-in hybrid vehicle market trends and policies in China, Europe, and the United States. (The International Council on Clean Transportation, Washington, DC, 2025).
30
Zhang, H. The Economic Impact of Different Government Policies on Hybrid Electric Vehicles (HEV) In Major Automobile Consumer Countries. Highlights in Business, Economics and Management 5, 96-100 (2023). https://doi.org:10.54097/hbem.v5i.5029
31
Dabush, I. & Cohen, C. Hybrids in the middle: PHEVs as bridge or lock-in to policy balance. Transportation Research Part D: Transport and Environment 154, 105250 (2026). https://doi.org:https://doi.org/10.1016/j.trd.2026.105250
32
de Sousa, G. C. & Castañeda-Ayarza, J. A. PESTEL analysis and the macro-environmental factors that influence the development of the electric and hybrid vehicles industry in Brazil. Case Studies on Transport Policy 10, 686-699 (2022). https://doi.org:https://doi.org/10.1016/j.cstp.2022.01.030
33
Oliveira Soares, L., Sodré, J. R., Hernández-Callejo, L., Duque de Brito, P. S. & Mancebo Boloy, R. A. Economic assessment of hybrid electric vehicles for sustainable transportation and decarbonization in Brazil. Energy 347, 140370 (2026). https://doi.org:https://doi.org/10.1016/j.energy.2026.140370
34
Carvalho, E. N. d., Pinho Brasil Júnior, A. C. & Brasil, A. C. d. M. Impact of electric vehicle emissions in the Brazilian scenario of energy transition and use of bioethanol. Energy Reports 10, 2582-2596 (2023). https://doi.org:https://doi.org/10.1016/j.egyr.2023.09.045

1
Agency, I. E. Energy Efficiency 2023. (IEA, Paris, 2023).
2
Talari, K. & Jatrothu, V. A Review on Hybrid Electrical Vehicles. Strojnícky časopis – Journal of Mechanical Engineering 72, 131-138 (2022). https://doi.org:10.2478/scjme-2022-0023
3
Yao, S. et al. 1237-1247 (2025).
4
Ikpe, A., Bassey, M. & Akpan, I. A Systematic Review of Hybrid Electric Vehicle Technologies and Their Impacts on Environmental Sustainability. Information Sciences and Technological Innovations 2, 1-23 (2025). https://doi.org:10.48314/isti.v2i1.28
5
Pan, Y. et al. A Review of Hybrid Vehicles Classification and Their Energy Management Strategies: An Exploration of the Advantages of Genetic Algorithms. Algorithms 18, 354 (2025).
6
Administration, U. S. E. I. Hybrid vehicle sales continue to rise as electric and plug-in vehicle shares remain flat, (2025).
7
Weiss, M., Zerfass, A. & Helmers, E. Fully electric and plug-in hybrid cars – An analysis of learning rates, user costs, and costs for mitigating CO₂ and air pollutant emissions. Journal of Cleaner Production 212, 1478-1489 (2019). https://doi.org:https://doi.org/10.1016/j.jclepro.2018.12.019
8
Lambros K. Mitropoulos, P. D. P., Pantelis Kopelias. Total cost of ownership and externalities of conventional, hybrid and electric vehicle. Transportation Research Procedia 24, 267-274 (2017).
9
Energy, U. S. D. o. U.S. HEV Sales by Model, (2025).
10
Wolfram, P. & Lutsey, N. Electric vehicles: Literature review of technology costs and carbon emissions. (2016).
11
Ferrer, A. L. C. & Thomé, A. M. T. Carbon Emissions in Transportation: A Synthesis Framework. Sustainability 15, 8475 (2023).
12
Singh, K. V., Bansal, H.O. & Singh, D. A comprehensive review on hybrid electric vehicles: architectures and components. Journal of Modern Transportation 27, 77-107 (2019).
13
Shrey Verma, G. D., Puneet Verma. Life cycle assessment of electric vehicles in comparison to combustion engine vehicles: A review. Materials Today: Proceedings 49, 217-222 (2022).
14
H.-O. Günther, M. K., N. Autenrieb. The role of electric vehicles for supply chain sustainability in the automotive industry. Journal of Cleaner Production 90, 220-233 (2015).
15
Ikpe, A., Bassey , M. ., & Akpan , I. A Systematic Review of Hybrid Electric Vehicle Technologies and Their Impacts on Environmental Sustainability. Information Sciences and Technological Innovations 2(1), 1-23 (2025).
16
Kumbar, P. Impact of Hybrid Vehicles on Fuel Economy and Emissions: A Comprehensive Analysis. World Journal of Advanced Research and Reviews 08(01), 307-319 (2020).
17
Carla Tagliaferri, S. E., Federica Acconcia, Teresa Domenech, Paul Ekins, Diego Barletta, Paola Lettieri. Life cycle assessment of future electric and hybrid vehicles: A cradle-to-grave systems engineering approach. Chemical Engineering Research and Design 112, 298-309 (2016).
18
Das, P. K., Bhat, M.Y. & Sajith, S. Life cycle assessment of electric vehicles: a systematic review of literature. Environmental Science and Pollution Research 31, 73-89 (2024).
19
P Lijewski, A. Z., P Daszkiewicz, M Andrzejewski and D Gallas. Comparison of CO₂ emissions and fuel consumption of a hybrid vehicle and a vehicle with a direct gasoline injection engine. IOP Conference Series: Materials Science and Engineering 421 (2018).
20
Laene Oliveira Soares, J. R. S., Ronney Arismel Mancebo Boloy. Lifecycle assessment and environmental impacts of hybrid electric vehicles fuelled by bioethanol and biogas. Renewable and Sustainable Energy Reviews 216 (2025).
21
Hartmann, P., Apaolaza, V., Eletxigerra, A., Barrutia, Jose M. & Echebarria, C. Beyond Climate Change Concern: Why Air Pollution Health Concern and Health Orientation Matter in Battery Electric Vehicle Adoption. Business Strategy and the Environment 34, 8020-8033 (2025). https://doi.org:https://doi.org/10.1002/bse.70003
22
Maesano, C. N. et al. Impacts on human mortality due to reductions in PM10 concentrations through different traffic scenarios in Paris, France. Science of The Total Environment 698, 134257 (2020). https://doi.org:https://doi.org/10.1016/j.scitotenv.2019.134257
23
Campello-Vicente, H., Peral-Orts, R., Campillo-Davo, N. & Velasco-Sanchez, E. The effect of electric vehicles on urban noise maps. Applied Acoustics 116, 59-64 (2017). https://doi.org:https://doi.org/10.1016/j.apacoust.2016.09.018
24
Heffner, R., Kurani, K. S, & Turrentine, T. S. Symbolism In Early Markets For Hybrid Electric Vehicles. (UC Davis: Institute of Transportation Studies, 2007).
25
Diamond, D. The impact of government incentives for hybrid-electric vehicles: Evidence from US states. Energy Policy 37, 972-983 (2009). https://doi.org:https://doi.org/10.1016/j.enpol.2008.09.094
26
Stephens, T., Zhou, Y., Burnham, A. & Wang, M. Incentivizing Adoption of Plug-in Electric Vehicles: A Review of Global Policies and Markets. (United States, 2018).
27
European Parliament & European Council. Official Journal of the European Union (2019).
28
Pavlovic, J., Ciuffo, B., Fontaras, G., Valverde, V. & Marotta, A. How much difference in type-approval CO₂ emissions from passenger cars in Europe can be expected from changing to the new test procedure (NEDC vs. WLTP)? Transportation Research Part A: Policy and Practice 111, 136-147 (2018). https://doi.org:https://doi.org/10.1016/j.tra.2018.02.002
29
Transportation, I. C. o. C. Plug-in hybrid vehicle market trends and policies in China, Europe, and the United States. (The International Council on Clean Transportation, Washington, DC, 2025).
30
Zhang, H. The Economic Impact of Different Government Policies on Hybrid Electric Vehicles (HEV) In Major Automobile Consumer Countries. Highlights in Business, Economics and Management 5, 96-100 (2023). https://doi.org:10.54097/hbem.v5i.5029
31
Dabush, I. & Cohen, C. Hybrids in the middle: PHEVs as bridge or lock-in to policy balance. Transportation Research Part D: Transport and Environment 154, 105250 (2026). https://doi.org:https://doi.org/10.1016/j.trd.2026.105250
32
de Sousa, G. C. & Castañeda-Ayarza, J. A. PESTEL analysis and the macro-environmental factors that influence the development of the electric and hybrid vehicles industry in Brazil. Case Studies on Transport Policy 10, 686-699 (2022). https://doi.org:https://doi.org/10.1016/j.cstp.2022.01.030
33
Oliveira Soares, L., Sodré, J. R., Hernández-Callejo, L., Duque de Brito, P. S. & Mancebo Boloy, R. A. Economic assessment of hybrid electric vehicles for sustainable transportation and decarbonization in Brazil. Energy 347, 140370 (2026). https://doi.org:https://doi.org/10.1016/j.energy.2026.140370
34
Carvalho, E. N. d., Pinho Brasil Júnior, A. C. & Brasil, A. C. d. M. Impact of electric vehicle emissions in the Brazilian scenario of energy transition and use of bioethanol. Energy Reports 10, 2582-2596 (2023). https://doi.org:https://doi.org/10.1016/j.egyr.2023.09.045