The primary difference between a PHEV (Plug-in Hybrid Electric Vehicle) and a REEV (Range-Extended Electric Vehicle) lies in how their gasoline engines are used: a PHEV can use its gasoline engine to directly power the wheels, while a REEV's gasoline engine only generates electricity to charge the battery.
Here's a more detailed breakdown:
PHEV (Plug-in Hybrid Electric Vehicle)
- Engine's Role: A PHEV combines an electric motor with a gasoline engine. Both can independently or jointly power the wheels.
- Battery Size: Typically has a smaller battery pack compared to a REEV.
- Operation:
- Can run on electric power alone for a limited range.
- When the battery is depleted, the gasoline engine can directly drive the wheels, functioning as a traditional hybrid.
- Example: Toyota Prius Prime, Mitsubishi Outlander PHEV.
REEV (Range-Extended Electric Vehicle)
- Engine's Role: A REEV primarily operates as an electric vehicle. The gasoline engine (sometimes referred to as an auxiliary power unit - APU) only acts as a generator to charge the battery and extend the driving range. The engine does not directly drive the wheels.
- Battery Size: Generally has a larger battery pack than a PHEV, allowing for greater electric-only range.
- Operation:
- Drives primarily on electric power.
- When the battery is low, the gasoline engine kicks in to generate electricity, recharging the battery and extending the vehicle's range. The wheels are still powered solely by the electric motor.
- Example: BMW i3 with Range Extender (discontinued, but a classic example).
Key Differences Summarized in a Table:
| Feature | PHEV (Plug-in Hybrid) | REEV (Range-Extended Electric Vehicle) |
|---|---|---|
| Engine's Role | Powers wheels directly or charges the battery. | Only charges the battery; does not directly power the wheels. |
| Battery Size | Smaller | Larger |
| Primary Power | Electric + Gasoline | Primarily Electric (gasoline engine acts as a generator) |
| Drivetrain | Electric motor(s) and combustion engine drive the wheels. | Electric motor(s) drive the wheels; combustion engine charges the battery. |
In essence, think of a PHEV as a hybrid that you can plug in, while a REEV is an electric car with a built-in generator. REEVs prioritize electric driving and use the gasoline engine only as a backup power source.
