Do We Still Use Combustion Engines?

Yes—combustion engines are still widely used across the world in road transport, aviation, shipping, agriculture, construction, and backup power. While electric and other zero-emission technologies are growing fast and many governments plan to end sales of new gasoline and diesel cars around 2035, internal combustion engines (ICE) remain dominant in today’s global fleet and will persist in many sectors for years due to long asset lifetimes, infrastructure, and technical constraints.

Where Combustion Engines Remain the Norm

Despite rapid progress in electrification, several industries still depend heavily on combustion because of energy density needs, operational demands, and infrastructure realities. The following sectors illustrate where ICE technology continues to be central.

• Light-duty road transport: Most of the world’s 1.4–1.5 billion cars are still ICE or hybrids; EVs are a fast-growing minority.
• Heavy-duty trucks and buses: Diesel dominates long-haul trucking; battery-electric adoption is rising for urban delivery and some bus routes.
• Aviation: Almost all commercial aircraft rely on turbine combustion engines; decarbonization focuses on sustainable aviation fuel (SAF) blends.
• Shipping: Large vessels primarily burn heavy fuel oil, marine gas oil, or LNG; methanol- and LNG-fueled newbuilds are growing, with ammonia under development.
• Agriculture and construction: Tractors, harvesters, excavators, and generators are largely diesel-powered; electrification is emerging for smaller equipment.
• Backup and remote power: Diesel and gas gensets provide emergency and off-grid electricity in hospitals, data centers, and remote sites.
• Small engines: Lawn and garden tools, outboard motors, and recreational vehicles still use small ICEs, though battery alternatives are expanding.

These uses reflect the current balance between energy needs, duty cycles, and the pace of infrastructure change; many are gradually transitioning but remain combustion-led today.

How Big Is the Combustion Footprint?

By most measures, internal combustion still accounts for the majority of energy use in transport. As of 2023–2024, EVs represented roughly a few percent of the global car fleet, even as they captured a rising share of new car sales in key markets. Aviation and deep-sea shipping remain almost entirely combustion-based, and non-road machinery is overwhelmingly diesel-powered. This means ICE vehicles and engines will be in service for decades, even as sales policies shift.

Policy: Where Sales Are Headed

Governments are tightening emissions rules and, in many cases, setting dates to end sales of new fossil-only passenger vehicles. Below is a snapshot of notable policies shaping the future of combustion engines in light-duty transport and beyond.

• European Union: From 2035, new cars and vans must meet zero tailpipe CO2 standards, with a narrow pathway for vehicles running exclusively on certified e-fuels; aviation faces ReFuelEU SAF blending mandates and shipping is covered by FuelEU Maritime and inclusion in the EU ETS.
• United Kingdom: Ends sales of new petrol/diesel cars in 2035; a Zero Emission Vehicle mandate ramps quotas through the 2020s.
• United States: California’s Advanced Clean Cars II targets 100% ZEV new car sales by 2035; multiple states are following. Federal EPA standards for model years 2027–2032 tighten fleet emissions, driving higher EV uptake.
• Canada: National sales mandate aims for 100% ZEV new light-duty vehicles by 2035, with interim targets.
• China: No fixed ICE ban, but strong “NEV” (battery-electric, plug-in hybrid, fuel cell) policies and credits; NEVs have surpassed 30% of new car sales in 2024 in major cities and continue to climb nationally.
• Japan and South Korea: Targets for high shares of electrified sales (including hybrids) by the 2030s; specific ZEV shares vary by policy pathway.

These policies largely affect new sales, not the use of existing vehicles, so ICE models already on the road will remain in service well beyond the cutoff dates.

Technology Outlook: What Changes for Combustion

Internal combustion is evolving rather than disappearing overnight. Several technical trends are reshaping how and where ICE will compete in the 2020s and 2030s.

• Hybridization: Pairing ICE with electric motors improves efficiency and cuts fuel consumption, extending ICE relevance in markets with limited charging.
• Advanced engine designs: Atkinson/Miller cycles, higher compression ratios, and improved aftertreatment reduce emissions and boost efficiency.
• Low-carbon liquid fuels: Biofuels in road diesel/gasoline and SAF in aviation reduce lifecycle CO2 where sustainably sourced; supply is limited and costlier.
• E-fuels (synthetic fuels): Produced from green hydrogen and captured CO2; compatible with existing engines but currently expensive and energy-intensive, likely niche for legacy fleets and aviation.
• Alternative combustion fuels: LNG and methanol are scaling in shipping; ammonia and hydrogen ICE are being trialed for heavy-duty and off-road niches.
• Electrification of components: 48V systems, electric turbo/superchargers, and electrified auxiliaries cut fuel use even in conventional platforms.

These developments suggest ICE will coexist with electrification, with the competitive edge shifting to hybrids, cleaner fuels, and specialized applications.

Environmental Context

Combustion engines emit CO2 and local pollutants (NOx, particulates). While modern aftertreatment can slash local emissions, decarbonizing combustion depends on cleaner fuels and higher efficiency. EVs generally deliver lower lifecycle emissions, especially as power grids add renewables. Biofuels and SAF can cut lifecycle CO2 but face feedstock and land-use constraints; e-fuels can be near-carbon-neutral if powered by renewable electricity but remain supply- and cost-constrained.

What This Means for Consumers and Operators

For most buyers, especially outside dense urban centers, ICE and hybrid vehicles remain available and supported. The following considerations can help anticipate the transition’s practical effects.

• Availability: New ICE models will continue this decade in many markets; model lineups will gradually shift toward hybrids and EVs.
• Operating costs: EVs often have lower fueling and maintenance costs where electricity is affordable; efficient hybrids narrow the gap where charging is sparse.
• Resale and policy zones: Low-emission zones, congestion pricing, and tax incentives can influence total cost of ownership and resale values.
• Fuel options: Blended biofuels are increasingly common; access to high-blend fuels or e-fuels will remain location- and price-dependent.
• Infrastructure: Charging and hydrogen networks are expanding unevenly; rural and heavy-duty use cases will transition more slowly.

The transition will not be uniform: geography, policy, and use case will determine whether combustion, hybrid, or electric is the best fit over the next decade.

Timeline: What to Expect

The pace of change will vary by region and sector. Broadly, the next 10–20 years will see a steady decline in new ICE sales for light vehicles, with heavy-duty, aviation, and maritime transitioning more gradually.

1. 2025–2030: Rapid EV growth in leading markets; hybrids remain strong globally; early scaling of SAF and methanol/LNG in shipping.
2. 2030–2035: Many jurisdictions approach or reach 100% ZEV targets for new light-duty sales; ICE persists in used market and in specialized segments.
3. 2035–2045: Fleet turnover significantly reduces ICE share in cars; combustion remains in aviation, maritime, and demanding off-road uses with cleaner fuels.

By mid-century, combustion engines are likely concentrated in sectors where energy density and range are paramount, increasingly paired with low-carbon fuels.

Summary

We still use combustion engines—and in most sectors, they remain the majority today. Policies and market trends are steering new light-duty sales toward zero-emission options by the mid-2030s in many regions, but the long lifespan of vehicles and the demands of aviation, shipping, heavy-duty transport, and off-road machinery mean combustion will remain part of the energy mix for decades. The future of ICE is narrower, cleaner, and more specialized, coexisting with rapidly expanding electric and other zero-emission technologies.

Will combustion engines be banned?

Combustion engines will not be banned from existence, but their sale will be phased out. California, and other states, plan to ban the sale of new gasoline-powered cars by 2035, with others potentially following suit. The European Union also had plans for a 2035 ban, but this is currently under reconsideration. The bans do not apply to existing vehicles, which can still be driven and sold, and they primarily target new vehicle sales rather than banning the engines themselves. 
What the Bans Mean

• No New Sales: The main focus is on the cessation of new vehicle sales. 
• Existing Cars Are Safe: You can continue to own, drive, and sell your current gasoline or diesel car. 
• Used Car Market: The bans do not affect the existing used car market. 
• Varying Regulations: The specifics and timing of bans will differ between countries and even states, with some opting for different approaches. 

Key Areas with Regulations

• United States: . Opens in new tabCalifornia’s Advanced Clean Cars II rule aims to have 100% of new passenger car and light truck sales be zero-emission vehicles (ZEVs) by 2035. Other states have also adopted similar goals. 
• European Union: . Opens in new tabThe EU had previously legislated a ban on new gasoline and diesel cars starting in 2035, but there are efforts to overturn or amend this ban. 

Why the Shift to Zero-Emissions? 

• Climate Change: A primary driver for these regulations is to reduce greenhouse gas emissions and combat climate change.
• Pollution: Regulations aim to cut harmful air pollution.
• Incentivizing EVs: The goal is to accelerate the transition to electric and other zero-emission vehicles.

What’s Next?

• Infrastructure: Significant investment is being made in the electrification of the auto industry and the necessary charging infrastructure. 
• Technological Advancements: The development of electric vehicles (EVs) and other zero-emission technologies is accelerating. 
• Continued Evolution: Governments and auto manufacturers are continuously adapting to new rules and technological advancements. 

Are combustion engines coming back?

Can internal-combustion engines stay relevant in an EV world? (Hint: the answer is yes). The internal-combustion engine is far from dead, and motorsports and aftermarket performance companies will play a key role in making ICE vehicles environmentally sound for decades to come.

Are combustion engines still used?

Yes, internal combustion engines (ICEs) are still widely used across various sectors, including nearly all heavy-duty vehicles, heavy machinery, aviation, and marine applications, and will remain relevant for decades. While the adoption of electric vehicles (EVs) is growing, the infrastructure for widespread EV use is still developing, and ICEs offer benefits like power and durability, especially in niche applications. Furthermore, ongoing development aims to improve ICE technology and utilize lower-carbon renewable fuels, ensuring their continued role in reducing carbon emissions.
 
Sectors still using ICEs:

• Heavy-Duty Transportation: Over 99% of commercial vehicles, including large trucks, use internal combustion engines. 
• Heavy Machinery: ICEs are essential for power generation, agriculture, construction, and other heavy-duty, off-road applications. 
• Aviation: Many general aviation and private aircraft still rely on piston engines, a type of internal combustion engine. 
• Marine: Internal combustion engines, particularly diesel, are used in many marine applications. 
• Specialty Vehicles: Powerful and lightweight engines for motorsports, racing, and some motorcycles also continue to use internal combustion technology. 

Reasons for continued use:

• Infrastructure Limitations: The global infrastructure is not yet prepared for a full transition to electric power. 
• Durability and Power: ICEs provide outstanding durability and can still provide the power needed for demanding applications. 
• Alternative Fuels: ICE technology can be adapted to use lower-carbon, renewable fuels such as biodiesel, hydrogen, renewable natural gas, and e-fuels, helping to reduce emissions. 
• Ongoing Development: Automakers and other industries are continuing to develop new and improved internal combustion engines to meet efficiency and emissions standards. 

What will replace the combustion engine?

But what will replace the conventional internal combustion engine? Two possibilities are the hybrid-electric engine and the hydrogen powered fuel cell. Automobiles with hybrid-electric engines are already available on a limited basis, while vehicles powered by hydrogen fuel cells are still years away.