Hybrid Cars Explained: How They Work and What to Maintain

 Hybrid cars are everywhere now, but many drivers still do not know how they work or how to look after them. In short, a hybrid has both a petrol (or diesel) engine and an electric motor with a battery. They work together to save fuel.

Hybrids combine a petrol engine with an electric motor.
Photo by Michail Dementiev on Unsplash

The three main types

• Mild hybrid: a small electric system that helps the engine, for example when you accelerate. The car cannot drive on electricity alone.
• Full hybrid: the car can move on the electric motor alone for short distances and at low speed. You never plug it in. The battery recharges while you drive and brake.
• Plug-in hybrid (PHEV): it has a bigger battery that you charge from a socket. It can drive a good distance on electricity, then the petrol engine takes over.

How the savings happen

When you brake or lift your foot, the electric motor works as a generator and sends energy back to the battery. This is called regenerative braking. The engine also switches off when the car is stopped or moving slowly, so you burn no fuel in traffic.

What still needs regular care

1. The petrol engine. It still needs oil changes, filters, spark plugs and coolant, as your manual says. Hybrid engines often stop and start many times, so do not skip the service.
2. The brakes. Regenerative braking means the brake pads may last longer, but they can rust or stick if they are used less. Have them checked regularly.
3. The 12-volt battery. Even a hybrid has a normal small battery, and it can fail like in any other car.
4. Tires. Check pressure and wear as usual.
5. The cooling system for the engine and for the electrical parts.

If you choose a plug-in hybrid

Charge it regularly. If you never plug it in, you carry a heavy battery around and you may use more fuel than in a normal car.

Safety note

The orange cables in a hybrid carry high voltage. Never touch or cut them. Leave any work on the high-voltage system to a trained technician, and follow your manual if you need to jump-start the car, because some models have special procedures.

Golden tip: Before buying a used hybrid, ask for the service history and for a battery health check.

Would you choose a hybrid for your next car? Tell us why in the comments.

This article is for general information only. Electric and hybrid cars differ a lot between makes and models, so always follow your owner's manual and let a qualified technician handle anything that involves the high-voltage system.