Industry & Classification

Vehicle Engine Types

Treating ICE to BEV as one electrification spectrum, HFCEV and hydrogen ICE are separated as a distinct hydrogen lane.

Classification criteria

Vehicle engine types cannot be decided by engine presence alone

Electrified vehicles should be read by whether an engine exists, whether it directly drives the wheels, whether external charging is possible, and where energy is stored.

The main axis shows the shift from ICE to BEV as electric drive share increases. MHEV and HEV keep engine-led layouts, PHEV adds an externally charged battery, and EREV is generally closer to motor-led drive.

EREV overlaps structurally with PHEV, but in most explanations it is positioned closer to BEV because the engine usually acts as a range-extending generator.

HFCEV and hydrogen ICE both use hydrogen, but they are fundamentally different: HFCEV is motor-driven, while hydrogen ICE combusts hydrogen in an engine.

Electrification level

Read a position by whether the motor is auxiliary, primary, or the vehicle can move only without an engine.

External charging

HEV is built on self-charging, while PHEV, EREV, and BEV charge from external power for driving.

Direct wheel drive

PHEV often allows direct engine drive, whereas EREV is more often described as motor-led drive.

Hydrogen branch split

HFCEV is a fuel-cell electric vehicle, and hydrogen ICE is an ICE vehicle; they are shown separately even with the same fuel.

Naming boundaries vary by manufacturer and market, so check actual driveline structure and charging method on real models.

Use points

Read vehicle descriptions

Quickly identify what powertrain structure MHEV, HEV, PHEV, EREV, and BEV mean in spec sheets and marketing copy.

Compare electrification position

Judge how close a model is to BEV by combining engine-wheel coupling and external charging availability.

Separate hydrogen variants

Even with the same fuel, HFCEV and hydrogen ICE use different drivetrains; do not place them on one axis.

Sources

Electrification position

From ICE to BEV, with hydrogen separated

The horizontal axis moves from engine-driven layouts toward motor-driven battery electric layouts.

Main electrification spectrum

Internal combustion engine ICE None

Mild hybrid electric vehicle MHEV Auxiliary

Hybrid electric vehicle HEV Partial

Plug-in hybrid electric vehicle PHEV High

Extended-range electric vehicle EREV Very high

Battery electric vehicle BEV Full

Separate hydrogen lane

HFCEV is motor-driven but stores energy differently from BEV; H2-ICE uses hydrogen in an engine.

Hydrogen fuel cell electric vehicle HFCEV Electric motor

Hydrogen internal combustion engine H2-ICE Hydrogen internal combustion engine

Types 8

Main spectrum 6

Hydrogen lane 2

Plug-in types 3

TABLE

Data preview

8 rows


ICE	Internal combustion engine	Main spectrum	None	Gasoline, diesel, LPG, and similar liquid or gaseous fuels	Engine	No	Yes	It burns fuel inside the engine to create power, then sends it through the transmission and driveshaft to directly drive the wheels.	Use this as the conventional ICE benchmark without a hybrid-assist motor.
MHEV	Mild hybrid electric vehicle	Main spectrum	Auxiliary	Fuel + small battery	Engine-led with electric motor assist	No	Yes	A small battery and motor support start, acceleration, and regenerative braking, but do not provide long-distance EV-only driving.	Do not assume standalone electric driving like HEV or PHEV in this efficiency-support structure.
HEV	Hybrid electric vehicle	Main spectrum	Partial	Fuel + self-charging battery	Engine and electric motor	No	Yes	Uses engine and electric motor together; the battery is recharged by regenerative braking and by engine operation.	There is no external charging port, so it must be distinguished from PHEV.
PHEV	Plug-in hybrid electric vehicle	Main spectrum	High	Externally charged electricity + fuel	Electric motor and engine	Yes	Usually yes	It runs electrically using grid-charged battery power, then uses both motor and engine after battery depletion.	Electric range and engine engagement behavior can vary widely by architecture.
EREV	Extended-range electric vehicle	Main spectrum	Very high	Grid electricity + range-extending fuel	Motor-centered	Yes	Usually no	Wheel drive is handled by an electric motor, while the engine mainly charges the battery or generates power to extend driving range.	Boundaries may overlap with PHEV depending on manufacturer, so confirm whether the engine directly drives the wheels.
BEV	Battery electric vehicle	Main spectrum	Full	Grid electricity	Electric motor	Yes	No	No combustion engine; it drives the motor using electricity stored in a battery.	Real emission context changes with grid generation mix and charging infrastructure.
HFCEV	Hydrogen fuel cell electric vehicle	Hydrogen lane	Electric drive	Hydrogen + fuel cell	Electric motor	Mostly no	No	Electricity generated by the hydrogen-oxygen electrochemical reaction is used to drive an electric motor.	It behaves like an EV in drive concept, but energy storage and supply differ from BEV; keep as a separate lane.
H2-ICE	Hydrogen internal combustion engine	Hydrogen lane	Engine drive	Hydrogen fuel	Hydrogen internal combustion engine	No	Yes	It produces engine power by combusting hydrogen instead of gasoline or diesel, then drives the wheels.	It uses hydrogen, but it is not a fuel-cell EV and still has internal-combustion-related emission management concerns.