What type of engine is used in cars?

Most cars still use four-stroke internal combustion engines—primarily gasoline (spark-ignition) or, less commonly today, diesel (compression-ignition). However, a fast-growing share of the market uses electrified powertrains: hybrids combine an engine with one or more electric motors, while battery-electric and hydrogen fuel-cell cars use electric motors only and have no conventional engine.

The mainstream: Internal combustion engines (ICE)

For more than a century, the internal combustion engine has powered the majority of passenger vehicles. These engines burn fuel-air mixtures inside cylinders to create pressure that turns the crankshaft. Modern ICEs use electronic fuel injection, precise ignition timing, variable valve timing, and often turbocharging to boost efficiency and power while meeting emissions rules.

Gasoline (spark-ignition) engines

Gasoline engines ignite a compressed fuel-air mixture with a spark plug. Today’s versions commonly feature direct injection, turbocharging, and advanced valve control. In many hybrids, the gasoline engine runs on an Atkinson or Miller-like cycle (achieved via valve timing) to prioritize efficiency over peak power, with the electric motor supplying extra torque when needed.

Diesel (compression-ignition) engines

Diesel engines ignite fuel by compressing air until it’s hot enough for combustion, delivering strong low-end torque and superior fuel economy, especially on highways. They require advanced aftertreatment—such as diesel particulate filters and selective catalytic reduction—to control soot and NOx. Following stricter emissions standards, diesel’s share in passenger cars has declined in many markets.

Electrified options reshaping the definition

Electrification ranges from mild hybrids to fully electric cars. Hybrids still include an engine, but battery-electric and fuel-cell vehicles do not—they use electric motors only. Market adoption has accelerated in recent years, supported by improving battery technology and policy incentives.

Hybrid electric vehicles (HEV, MHEV, PHEV)

Hybrids blend combustion and electric drive. A mild hybrid (MHEV) can’t drive on electricity alone but assists the engine; a full hybrid (HEV) can move short distances electrically; a plug-in hybrid (PHEV) offers a larger battery and meaningful electric-only range before the engine engages for longer trips.

Battery-electric vehicles (BEV)

BEVs have no engine. They use one or more electric motors powered by a battery pack that’s charged from the grid. They deliver instant torque, quiet operation, and zero tailpipe emissions, with range and charging speed improving steadily.

Fuel-cell electric vehicles (FCEV)

FCEVs generate electricity on board from hydrogen using a fuel cell and power an electric motor. They emit only water vapor at the tailpipe but depend on hydrogen refueling infrastructure, which remains limited in most regions.

Hydrogen internal combustion (H2 ICE)

A niche and emerging approach uses modified combustion engines to burn hydrogen. Automakers and suppliers have demonstrated prototypes, but real-world availability is limited compared with BEVs and hybrids.

Common engine layouts and configurations

Beyond fuel type, engines are built in various configurations to balance smoothness, packaging, cost, and performance. The following are the forms most drivers are likely to encounter:

• Inline-3 and inline-4: Compact, efficient, widely used in small to midsize cars and crossovers.
• Inline-6: Smooth, balanced, and increasingly popular again due to modular designs and turbocharging.
• V6 and V8: Higher power and towing capability; common in performance and larger vehicles.
• Flat (boxer) four or six: Low center of gravity; used by brands such as Subaru and Porsche.
• Rotary (Wankel): Rare in modern cars; occasionally used as a small range-extender generator in some plug-in models.
• Two-stroke: Very uncommon in passenger cars today; the four-stroke cycle dominates.

Each layout makes trade-offs: inline engines simplify manufacturing and packaging, V engines can fit more cylinders in less length, and boxers lower the center of gravity for improved handling.

Operating cycles and boosting technologies

Engines differ not only in layout but in how they breathe and convert fuel into motion. Several cycles and technologies define how modern engines achieve performance and efficiency.

• Otto cycle: The standard for most gasoline engines.
• Diesel cycle: Higher compression and efficiency, typical of diesel engines.
• Atkinson/Miller cycle: Often used in hybrids via valve timing strategies to improve efficiency.
• Turbocharging and supercharging: Force more air into the engine for higher power from smaller displacements.
• Direct injection and variable valve timing/lift: Precisely control fuel and airflow to boost efficiency and reduce emissions.

Taken together, these advances let smaller engines deliver the power once reserved for larger units while meeting tighter emissions and fuel-economy standards.

Fuel choices powering today’s engines

The fuel an engine burns has a major impact on performance, emissions, cost, and availability. Traditional options are joined by alternatives aimed at reducing carbon intensity.

• Gasoline: Ubiquitous, with octane ratings matched to engine design.
• Diesel: Energy-dense, efficient on highways and under load.
• Ethanol/flex-fuel (e.g., E85): Higher octane; availability varies by region.
• Compressed natural gas (CNG) and liquefied petroleum gas (LPG): Lower CO2 per unit of energy; niche markets.
• Biodiesel and renewable diesel: Drop-in or blended options for compatible diesel engines.
• Synthetic e-fuels: Early-stage, potentially carbon-neutral when made with renewable energy; limited supply and high cost.
• Hydrogen: Used in fuel cells or experimental hydrogen ICEs; infrastructure is sparse.

While gasoline remains dominant in passenger cars, policy shifts and technology improvements are steadily expanding the role of lower-carbon fuels and electric energy.

Which is right for you?

Choosing between engine and powertrain types depends on how and where you drive, refueling/charging access, and budget priorities.

• Primarily city driving: Full hybrid or BEV for efficiency and low operating costs.
• Long highway trips or towing: Efficient ICE (often turbo gasoline) or diesel where available; PHEV if you want electric miles plus road-trip flexibility.
• No home charging: Hybrid (HEV/MHEV) keeps fuel use down without plugging in.
• Performance focus: Turbocharged gasoline or dual-motor BEVs for instant torque.
• Cold climates: BEVs work well with proper battery thermal management; hybrids and ICEs remain robust where charging is limited.

Match the powertrain to your daily pattern first, then consider total ownership costs, local fuel/electricity prices, and available incentives.

Summary

Cars traditionally use four-stroke internal combustion engines, chiefly gasoline and, to a lesser degree today, diesel. Electrification is rapidly changing the landscape: hybrids pair engines with electric motors, while battery-electric and fuel-cell models rely solely on electric drive and have no engine. Engine layouts (inline, V, flat), operating cycles (Otto, Diesel, Atkinson/Miller), and technologies like turbocharging and direct injection shape how modern cars deliver power and efficiency. Your best choice depends on driving habits, infrastructure, and ownership priorities.

Do cars have V8 engines?

Most V8 engines produced in the automotive industry produce good power despite their high production capability. A vehicle equipped with an eight-cylinder engine isn’t always the best one. Many cars use V8 engines.

Which is better, a 3 or 4 cylinder engine?

Three cylinder engines produce more power per cycle compared to four cylinder, weighs less, has lower moving parts, occupies less space, gives more fuel efficiency and cheaper to maintain compared to four cylinder engine but would vibrate more due to improper counter balancing.

Which is better v4 or V6 engine?

While there are some speedy four-cylinder engines, a V6 is generally more responsive and provides faster acceleration times. If you’re looking for a powerful driving experience, a V6 engine will deliver that feeling. The choice between the two engines also depends on the size of the SUV you are interested in.

What is the most used type of engine?

Inline engines, also referred to as straight engines, are one of the most common types of engine configurations found in passenger cars. This type of engine aligns its cylinders in a straight row. The alignment can be horizontal or vertical, depending on the car’s design.