Understanding Mild Hybrids vs Full Hybrids

Buying a car, whether new or used, can be both exciting and challenging. One aspect that often confuses buyers is What is a mild hybrid?. This confusion can either deter them from purchasing or lead them to make the wrong choice. Some might joke that mild hybrids are like a guinea pig—neither a guinea nor a pig…

The Challenge of Finding Non-Hybrid Models

A buyer might find themselves in a situation where they literally can’t find the desired model that isn’t a mild hybrid. This can be very frustrating, especially if they think it’s a full hybrid, like the Toyota Prius, but are determined to buy a car with a conventional engine.

Therefore, it’s increasingly important for drivers to understand the differences between types of powertrains and various systems. This knowledge helps them make an informed decision when purchasing a car.

What Sets Mild Hybrids Apart?

A mild hybrid, also known as a mild hybrid electric vehicle” (MHEV), differs from a full hybrid because it cannot drive on electricity alone. Instead, it uses various “tricks” to reduce fuel consumption.

Specifically, a mild hybrid features a starter-generator that functions as both a starter motor and an alternator. This starter-generator assists the standard gasoline or diesel engine during starts, sharp accelerations, and overtaking.

The system relies on a small lithium-ion battery that charges during driving, similar to the battery in a full hybrid. Although this starter-generator can’t move the car on its own and the battery capacity is limited, their combination still offers several advantages.

Advantages of a Mild Hybrid System

This type of hybrid vehicle uses its lithium-ion battery to reduce fuel consumption in several ways. For instance, the battery powers various devices and systems while the gasoline/diesel engine is off. This feature allows the engine to shut off earlier when stopping at traffic lights and to remain off longer during stops, even if many consumers are active, such as air conditioning, window heaters, or mirrors.

The mild hybrid system can lower fuel consumption by 5% to 15%. Although it may not offer dramatic fuel savings, it helps significantly in city driving, especially in stop-and-go scenarios where the engine repeatedly starts and stops.

Additionally, it reduces fuel consumption and CO2 emissions, and some mild hybrids cut nitrogen oxide emissions by as much as 50% to 60%.

Identifying Mild Hybrid Vehicles

There is no universal answer to this question. Some models use the letter “e” in the engine/powertrain designation. Many have no additional designation, and some even use the word “Hybrid” in the model version name (without the word “mild”), even though it is actually a mild hybrid. Therefore, always gather information in advance, whether you’re looking at a new or used car.