What kind of engines do cars use?

Most cars still use internal combustion engines—primarily gasoline (spark‑ignition) and diesel (compression‑ignition)—while a fast‑growing share use electric motors, and many combine both in hybrid systems. As electrification accelerates worldwide, buyers now encounter a spectrum of powertrains ranging from traditional engines to fully electric drivetrains and niche alternatives.

The main categories at a glance

The following list summarizes the principal types of propulsion powering cars on the road today, from conventional engines to emerging options.

• Gasoline internal combustion engines (ICE): spark-ignition units using Otto, Atkinson, or Miller cycles; dominate global passenger cars.
• Diesel internal combustion engines: compression-ignition units valued for torque and efficiency; common in trucks and some SUVs, less so in new passenger cars in many regions.
• Hybrid powertrains (engine + electric motor): includes mild hybrids (48V), full hybrids (self-charging), plug-in hybrids (PHEV), and range-extender setups.
• Battery-electric vehicles (BEV): use electric motors only (no engine) with energy from a battery.
• Fuel-cell electric vehicles (FCEV): generate electricity onboard from hydrogen in a fuel cell to drive electric motors (no engine).
• Hydrogen internal combustion engines (H2 ICE): experimental/limited deployment, burning hydrogen in a modified ICE.
• Rotary (Wankel) engines: rare today; occasionally used as compact range extenders.
• Alternative-fuel ICE: operate on CNG/LPG, flex-fuel ethanol blends (e.g., E85), or synthetic e‑fuels.

Taken together, gasoline ICEs remain the most common globally, hybrids are expanding rapidly, and electric-only drivetrains now account for roughly one in five new car sales in many markets, reflecting a clear shift toward electrification.

How internal combustion engines differ

Gasoline engines (spark-ignition)

Gasoline engines ignite a fuel–air mixture with a spark plug. Modern designs favor smaller, turbocharged units with direct injection for efficiency and power, often paired with particulate filters to reduce soot. Variants include Atkinson- or Miller-cycle engines (common in hybrids) that trade peak power for superior efficiency. Pros include smoothness, lower NOx emissions, broad availability, and lower initial cost; cons include higher CO₂ per mile than diesel under load and rising complexity to meet emissions rules.

Diesel engines (compression-ignition)

Diesels compress air until it’s hot enough to ignite injected fuel, producing strong low-end torque and better thermal efficiency. They require advanced aftertreatment—diesel particulate filters (DPF) and selective catalytic reduction (SCR/AdBlue)—to control particulate and NOx emissions. While diesel’s share of new passenger cars has declined in many regions, it remains important for heavy-duty applications and long-distance driving due to efficiency and towing capability.

Alternative fuels in ICE

Some ICE models are built or adapted for specific fuels: flex-fuel gasoline/ethanol (common in Brazil and parts of North America), compressed natural gas (CNG) and liquefied petroleum gas (LPG) fleets in select markets, and emerging hydrogen ICE prototypes. Synthetic e-fuels—produced with captured CO₂ and green hydrogen—are being piloted for legacy performance models and niche use where electrification is difficult, though production volumes and costs remain limiting.

Engine layouts and cylinder configurations

Layout and cylinder count shape a car’s packaging, balance, smoothness, and cost. These are the most common configurations you’ll encounter.

• Inline engines: I3 and I4 dominate compact to midsize cars; I6 is prized for smoothness and is resurging in some premium and truck platforms.
• V engines: V6 and V8 are common for performance and towing; larger V10/V12 are now rare and mostly found in legacy or exotic models.
• Flat/boxer engines: horizontally opposed designs (H4, H6) offer a low center of gravity; used by a few manufacturers.
• VR/W engines: compact “narrow-angle” V or multi-bank W layouts (e.g., VR6, W12) appear in specific legacy or high-performance applications.
• Rotary (Wankel): compact and smooth but historically challenged by emissions and fuel economy; niche use as a generator in some range-extender hybrids.

The choice of layout reflects trade-offs: inline engines are cost-effective and compact, V engines package well for higher cylinder counts, and boxer layouts aid handling by lowering mass, all while influencing refinement and serviceability.

Key technologies shaping modern engines

To meet efficiency, performance, and emissions goals, contemporary engines integrate a suite of advanced technologies.

• Forced induction: turbocharging (most common) and supercharging boost power and allow smaller, lighter engines.
• Fuel systems: gasoline direct injection (GDI) for precise metering; many pair with port injection to mitigate deposits and particulates (often with gasoline particulate filters, GPF).
• Valve and compression strategies: variable valve timing/lift, cylinder deactivation, and even variable compression ratios (e.g., VC-T) improve efficiency across load conditions.
• Hybridization: 48V mild-hybrid systems, regenerative braking, and engine stop-start reduce fuel use and smooth drivability.
• Thermal and emissions controls: cooled EGR, sophisticated cooling circuits, active aero shutters, and robust aftertreatment reduce emissions and speed warm-up.
• Advanced combustion: Atkinson/Miller cycles in hybrids, spark-controlled compression ignition (e.g., SPCCI) concepts, and research into homogeneous/partially premixed modes aim for diesel-like efficiency with lower emissions.

Together, these measures keep ICEs competitive under tightening regulations, though they add complexity and cost—one reason hybrids and EVs are proliferating.

Electrified and electric powertrains

Hybrids and plug-in hybrids (engine + motor)

Hybrids blend an engine with one or more electric motors. Architectures include parallel (engine and motor both drive wheels), series (engine acts as a generator only), and power-split systems that mix both modes. Full hybrids prioritize efficiency with Atkinson-cycle engines; plug-in hybrids add larger batteries for 20–60+ miles of electric range, ideal if regular charging is available. Some niche models use compact engines—occasionally rotary units—solely as generators (range extenders).

Battery-electric drive (no engine)

BEVs use electric traction motors—typically permanent-magnet synchronous motors, induction motors, or switched-reluctance designs—paired with single- or two-speed gearboxes. They deliver instant torque, high efficiency, and zero tailpipe emissions, with overall impact dependent on the electricity mix. As charging networks and battery tech improve, BEVs are capturing a growing share of new car sales.

Fuel-cell electric (no engine)

FCEVs generate electricity from hydrogen in a fuel cell to power motors, emitting only water vapor at the tailpipe. Limited hydrogen infrastructure and high system costs constrain adoption, but they remain an option in select markets and fleets.

What does the near future look like?

Policy and market signals point to a diversified decade. The European Union targets only zero-emission new car sales from 2035 with a carve-out for e-fuels under strict conditions; the United States and China are tightening fleet emissions and boosting incentives for electrified vehicles. Globally, EVs account for roughly one in five new cars, with hybrids growing quickly as a bridge technology. ICEs persist in markets with sparse charging or heavy towing needs, while niche fuels (CNG, e-fuels, hydrogen ICE) see targeted use rather than mass-market adoption.

Choosing based on needs

The best powertrain depends on where and how you drive, what you can refuel or recharge with, and your cost and regulatory environment. Consider the scenarios below as a practical guide.

• Urban commuting and stop‑go traffic: full hybrids or BEVs excel in efficiency and low running cost.
• Long highway trips or heavy towing: efficient turbo gasoline, diesel (for heavy-duty), or robust plug-in hybrids if you can charge at both ends.
• Performance driving: turbocharged gasoline engines and high‑performance EVs both deliver strong acceleration; ownership costs and range needs differ.
• Rural areas with limited charging: conventional gasoline or diesel may be simpler today; mild hybrids add efficiency without relying on plugs.
• Total cost of ownership: weigh fuel/electricity prices, incentives, maintenance (EVs often lower), and resale trends in your region.

Matching technology to your use case—and local infrastructure—will determine real-world costs, convenience, and environmental impact.

Summary

Cars today are powered primarily by gasoline and diesel internal combustion engines, with hybrids and fully electric drivetrains rapidly gaining share. Engine types vary by combustion method, fuel, and cylinder layout, while modern technologies—turbocharging, direct injection, variable timing, and hybridization—stretch efficiency and performance. Electric motors are replacing “engines” outright in BEVs and FCEVs, and policy trends suggest a continued shift toward electrification, with ICEs remaining where they still fit best.

What are the 4 types of engines?

Four types of engine, categorized by fuel and energy conversion, include Internal Combustion Engines (ICE) like petrol and diesel, External Combustion Engines such as steam engines, Electric Motors, and Hybrid Engines which combine ICE and electric power. These engine types can be further classified by their cylinder arrangement (e.g., Inline, V, Flat) or operating principles (e.g., gasoline vs. diesel).
 
Here are some common types of engines:
1. Internal Combustion Engines (ICE)

• How they work: Fuel combustion occurs inside the engine, generating heat that drives mechanical energy. 
• Examples: Petrol engines, diesel engines, gas turbines, and most car engines. 
• Subtypes:
  • Spark Ignition: Uses a spark plug to ignite the fuel-air mixture, like most gasoline engines. 
  • Compression Ignition: Compresses air to a high temperature, causing the fuel to ignite without a spark, characteristic of diesel engines. 

2. External Combustion Engines

• How they work: Fuel combustion takes place outside the engine, heating a working fluid (like water or air) that then performs work. 
• Examples: Steam engines and Stirling engines. 

3. Electric Motors 

• How they work: Convert electrical energy into mechanical energy.
• Characteristics: Clean operation with no combustion, making them environmentally friendly.

4. Hybrid Engines 

• How they work: Combine an internal combustion engine with an electric motor to optimize fuel efficiency and reduce emissions.
• Benefits: Offer flexibility with different modes of operation, such as electric-only or combined power.

Other Classifications
Engines can also be categorized by other factors: 

• Cylinder Arrangement:
  • Inline (or Straight): Cylinders are arranged in a single line. 
  • V-Type: Cylinders are arranged in a V-shape. 
  • Flat (or Boxer): Cylinders are arranged horizontally opposite each other. 
• Fuel Type: Gasoline, diesel, and renewable fuels like bioethanol. 
• Operating Cycle: Two-stroke and four-stroke engines, differentiated by their operational cycles. 

Which is better v4 or V6 engine?

A V6 is “better” than a four-cylinder engine for drivers prioritizing power, torque, and smoothness, especially for heavy loads or spirited driving, while a four-cylinder engine is generally “better” for fuel efficiency and cost, though modern turbocharging has made four-cylinder engines very powerful. The best choice depends on your specific needs and priorities, such as the type of vehicle, driving conditions, and budget. 
Choose a V6 if you need:

• More Power and Torque: Opens in new tabV6 engines typically offer higher horsepower and torque, providing faster acceleration and better responsiveness, especially when carrying heavy loads or in larger vehicles like SUVs and trucks. 
• Smoother and Quieter Driving: Opens in new tabThe inherent design of a V6 engine results in smoother operation and a more pleasant, less “agricultural” sound, making for a more comfortable and refined driving experience. 
• Better Towing and Hauling: Opens in new tabThe increased power and torque of a V6 make it better suited for towing heavy trailers or hauling significant cargo. 
• Less Strain on the Engine: Opens in new tabA V6 engine often operates at lower RPMs, meaning it isn’t working as hard as a smaller engine would for similar tasks, which can contribute to better longevity and reliability. 

Choose a four-cylinder if you prioritize:

• Fuel Economy: Opens in new tabFour-cylinder engines are generally more fuel-efficient, resulting in lower fuel costs compared to V6 engines. 
• Lower Purchase Cost: Opens in new tabVehicles with four-cylinder engines are often less expensive to buy than those with V6s. 
• Lighter Vehicles: Opens in new tabSmaller, compact cars are typically well-suited for four-cylinder engines, offering a good balance of performance and efficiency. 
• Modern Turbocharging: Opens in new tabAdvanced turbocharging technology has significantly boosted the output of many four-cylinder engines, allowing them to provide performance that rivals or even exceeds some naturally aspirated V6s in certain applications. 

Considerations for Both:

• Vehicle Type: Opens in new tabThe appropriate engine size often depends on the vehicle; a V6 is often necessary for the power required by larger trucks and SUVs, while smaller cars often suffice with a four-cylinder. 
• Modern Technology: Opens in new tabThe gap in performance between four-cylinder and V6 engines has narrowed significantly due to advancements like turbocharging and direct injection, so it’s important to look at specific models rather than generalizing based solely on the number of cylinders. 

What engines do most cars use?

Most cars today are powered by four-cylinder inline engines. These engines are common because they are efficient and provide a good balance of power and economy for everyday vehicles. Other popular engine types include inline-six and V-six engines for more powerful cars and trucks, and V-eight engines for luxury and high-performance vehicles. 
Common Engine Types by Cylinder Count:

• Four-Cylinder Engines: Opens in new tabThese are the most prevalent in the market, found in a majority of small-to-mid-size cars. 
• Six-Cylinder Engines: Opens in new tabOften found in SUVs, luxury sedans, and sports cars, these can be in an inline or a V-engine configuration. 
• V-Eight Engines: Opens in new tabTypically reserved for higher-end luxury cars and sports cars, they offer significant power. 

Engine Layouts:

• Inline (Straight) Engines: Opens in new tabThe cylinders are arranged in a single, straight line. This is the most common layout, especially for four-cylinder engines. 
• V-Engines: Opens in new tabCylinders are arranged in two banks, forming a “V” shape. This layout allows for more cylinders in a compact space. 

Why the Four-Cylinder Is So Popular:

• Efficiency: Four-cylinder engines are known for their excellent fuel economy, a major factor in their widespread adoption. 
• Versatility: The introduction of turbochargers has allowed manufacturers to significantly increase the power of four-cylinder engines, making them suitable for a wider range of vehicles. 

Which car has a V12 engine?

Cars with V12 engines include current and recent models from luxury and exotic brands like the Ferrari 12Cilindri, Lamborghini Revuelto, Aston Martin Vanquish, Rolls-Royce Phantom, and Mercedes-Maybach S680. Older, iconic V12 cars also exist from brands like Cadillac, Packard, and Lincoln. 
Examples of V12 Cars

• Ferrari: The 12Cilindri, 812 Superfast, and Purosangue feature V12 engines. 
• Lamborghini: The Revuelto, a hybrid supercar, uses a V12 as its primary engine. 
• Aston Martin: Models like the Vanquish, DB11, and Vantage are known for their V12 engines. 
• Rolls-Royce: Luxury models such as the Phantom and Ghost use V12 powerplants. 
• Mercedes-Benz: The Maybach S680 and the older AMG S65 feature a twin-turbo V12. 

Historical Context
V12 engines are most commonly found in high-performance and luxury vehicles. While less common today due to the rise of turbocharged V8s and hybrid powertrains, they are still a hallmark of certain brands, particularly in their flagship models. 
Used V12 Cars 

• For those interested in more affordable V12 options, the used car market offers many models from the brands listed above.