Car care · Elgin Auto Sales & Service Center · Elgin, IL
How Do Hybrid Cars Work?
Shopping for a used hybrid, or just curious what is under the hood? This guide explains how a hybrid electric car works, following fueleconomy.gov and the Alternative Fuels Data Center (afdc.energy.gov).
Engine + motortwo power sources
No pluga regular hybrid charges itself
Regenerativebraking recaptures energy
24% to 38%of fuel energy moves the car
The short answer
A hybrid electric car is powered by a gasoline engine and one or more electric motors that use energy stored in a battery. A regular hybrid cannot be plugged in: the battery is charged by regenerative braking and by the engine. The electric motor helps the engine accelerate, pass and climb hills, which allows a smaller, more efficient engine, and in some hybrids the motor alone moves the car at low speeds. The engine also shuts off when the car stops. That is why hybrids are most efficient in stop-and-go city driving.
The three technologies most hybrids use
Hybrid electric vehicles combine a gasoline engine with electric motors and can be designed for better fuel economy or for more power. Fueleconomy.gov says most hybrids use these technologies:
| Technology | What it does |
|---|---|
| Regenerative braking | Recaptures energy normally lost when coasting or braking. The forward motion of the wheels turns the motor, which generates electricity and helps slow the car. |
| Electric motor drive and assist | The motor adds power to help the engine accelerate, pass or climb hills, which allows a smaller, more efficient engine. In some hybrids the motor alone propels the car at low speeds, where gasoline engines are least efficient. |
| Automatic stop/start | Shuts the engine off when the car comes to a stop and restarts it when you press the accelerator, which cuts the energy wasted idling. |
From How Hybrids Work (fueleconomy.gov), read November 9, 2026.
The main parts of a hybrid car
The Alternative Fuels Data Center lists these key components of a hybrid electric car:
- Traction battery pack: stores electricity for the electric traction motor.
- Electric traction motor: uses power from the traction battery to drive the wheels. Some cars use motor generators that both drive and regenerate.
- Electric generator: generates electricity from the rotating wheels while braking and sends it back to the traction battery.
- Power electronics controller: manages the flow of electricity from the traction battery and controls the motor's speed and torque.
- DC/DC converter: converts higher-voltage power from the traction battery to the lower voltage needed for accessories and to recharge the auxiliary battery.
- Auxiliary battery: the low-voltage battery that starts the car before the traction battery is engaged and powers accessories.
- Gasoline engine, fuel tank and exhaust: a spark-ignited engine fed from an on-board gasoline tank, with a three-way catalyst in the exhaust to reduce emissions.
- Transmission and thermal system: the transmission sends power from the engine and/or motor to the wheels, and the cooling system keeps the engine, motor and power electronics in their operating range.
From How Do Hybrid Electric Cars Work? (Alternative Fuels Data Center), read November 9, 2026. A hybrid electric car cannot be plugged in to charge its battery; plug-in hybrids are a different type of vehicle.
Why hybrids save the most gas in the city
Fueleconomy.gov estimates that about 24% to 38% of the energy in the fuel you put in a hybrid is used to move it down the road, depending on the drive cycle. Hybrids are more efficient than comparable conventional cars, especially in stop-and-go driving. Two main reasons:
- Less idling. The engine turns off when the car stops and restarts when you press the accelerator, and city driving includes a lot of idling.
- Energy recovered from braking. In a conventional car, braking turns the car's motion into heat at the brakes. A hybrid's motor-generator turns some of it into electricity stored in the battery for later use, and there is more braking in stop-and-go traffic.
Like a conventional car, most of the fuel energy in a hybrid is still lost in the engine, mainly as heat, and some goes to the driveline and accessories. Seat and steering wheel heaters and climate control fans use more power than small items like door locks and signal lights.
From Where the Energy Goes: Hybrids (fueleconomy.gov), read November 9, 2026.
Service at Elgin Auto Sales & Service Center
Need maintenance or a check of your car's systems? Schedule service or see our service specials.
Our service department at 1200 E. Chicago St. in Elgin is open Monday to Friday 8 a.m. to 5 p.m. and Saturday 8 a.m. to 4 p.m., and is closed Sunday. Get directions.
Hybrid car FAQ
Do you have to plug in a hybrid car?
No. A regular hybrid electric car cannot be plugged in. Its battery is charged through regenerative braking and by the gasoline engine, according to the Alternative Fuels Data Center.
How does a hybrid charge its battery?
Through regenerative braking, which uses the turning wheels to drive a motor-generator when you coast or brake, and by the internal combustion engine.
Can a hybrid run on electricity alone?
In some hybrids the electric motor alone propels the car at low speeds, where gasoline engines are least efficient, fueleconomy.gov says.
Why are hybrids better in city driving?
Stop-and-go driving has more idling and more braking. A hybrid shuts its engine off at stops and recovers braking energy, so it is most efficient in the city.
What is the difference between a hybrid and a plug-in hybrid?
A regular hybrid cannot be plugged in; it charges its battery itself. Plug-in hybrids are a different type of vehicle.
What are your service hours?
Monday to Friday 8 a.m. to 5 p.m. and Saturday 8 a.m. to 4 p.m. We are closed Sunday.
Looking at a used hybrid?
Visit us at 1200 E. Chicago St. in Elgin.
Sources
How hybrids work is from fueleconomy.gov, administered for the U.S. Department of Energy and the EPA, and from the Alternative Fuels Data Center (afdc.energy.gov), read November 9, 2026. This is general information; your owner's manual is the authority for your vehicle. Our address and service hours are from our own website, checked the same day. Photo is of our dealership.
- How Hybrids Work (fueleconomy.gov), U.S. Department of Energy and U.S. EPA, read November 9, 2026
- How Do Hybrid Electric Cars Work? (Alternative Fuels Data Center), Alternative Fuels Data Center, read November 9, 2026
- Where the Energy Goes: Hybrids (fueleconomy.gov), U.S. Department of Energy and U.S. EPA, read November 9, 2026
- Home page: address, Elgin Auto Sales & Service Center, read November 9, 2026
- Service page: service hours, Elgin Auto Sales & Service Center, read November 9, 2026