Hybrid Electric

Hybrid Electric Vehicles

2016 Toyota Prius Hybrid Car

The Ultimate Information Guide to Understand Hybrid Cars

Hybrid cars have been in the U.S. market since late 1999. However in recent years, the right mix of fuel economy, affordability, and overall reliability has reinvigorated consumer interest in the Hybrid car market. For many shopping for an alternative fuel vehicle, hybrid vehicles act as a convenient alternative, as they can be regularly refueled like regular cars and need not rely on an electric charge to operate. Below, we explore what this new technology is, how it works, what the categories are, as well as the pros-and-cons.

What Are Hybrid Cars?


Hybrid Car Definition

Hybrid cars (sometimes referred to as "HEV" short for Hybrid Electric Vehicles) use more than one form of energy for power and propulsion. Most hybrid cars use 1) an internal combustion engine and 2) a battery-powered electric motor. Hybrid cars can be explained on further level by various categories, including Plug In hybrids, Parallel Hybrids, and Mild Hybrids.


Hybrid Cars Explained

Conventional vehicles are powered by a combustion engines, which run on either gasoline or a diesel fuel. Hybrid cars use these same internal combustion engines—and can even be fueled like them—however, they also have an electric battery powered motor. The car's basic goal is to maximize the use of the electric portion of the drivetrain to increase efficiency.

The benefit of hybrid vehicles lie in the fact that they can drive extended ranges (similar to their gasoline powered counterparts), while offering increased levels of efficiency. Hybrid cars are sometimes mistakenly confused with fully electric vehicles. While they do have electric motors, hybrid cars are mostly gasoline-burning machines that only utilize their electrical components to collect and reuse normally wasted energy. The exact methodology and extent that hybrid vehicles utilize their electronic components vary, as they are classified into different categories of hybrids (see below).

2016 Toyota Prius Hybrid Car
2016 Toyota Prius

How Do Hybrid Cars Work?

Hybrid-Electric Vehicles (HEVs) combine the respective benefits of gasoline powered engines and electric motors, creating a best of both worlds scenario. They can be configured to obtain different objectives, such as favorable fuel economy, increased power, or a combination of both.

The following technologies are core components to hybrid cars:

  1. Electric Motor ( also called Drive Assist, Motor-generator, or Electric Drive) - In a hybrid electric vehicle, the electric motor provides additional power to assist the engine in accelerating, passing, or hill climbing. In some vehicles, the electric motor by-itself can provide enough power for low-speed driving, where internal combustion engines are least efficient. While they mostly only provide supplemental acceleration, the maximum speed and distance over which electric-only operation can be sustained varies from essentially zero to a handful of miles, and is dependant on weight, aerodynamics, and battery capacity, among other things.

  2. Regenerative Braking - Normal cars will waste all of their excess momentum in the form of heat in the brakes. In hybrid vehicles, regenerative brakes absorb a portion of the vehicle's momentum when slowing or coasting downhill and converts it into electricity. How does this work? The electric motor applies resistance to the drivetrain causing the wheels to slow down. In return, the energy from the wheels turns the motor, which functions as a generator, converting energy normally wasted during coasting and braking into electricity, which is stored in a battery until needed by the electric motor. Regenerative braking is insufficient to stop a car quickly, so conventional hydraulic brakes are still necessary.

  3. Auto Start/Stop (also called Automatic Start Stop, Start-Stop System, Idle-Stop, or Idle-Off) - This feature automatically shuts the engine off when the vehicle comes to a stop and restarts it when the accelerator is pressed. This equates to no fuel being burned while the car is idling. Hybrid-control software will shut the engine off while stopped at a traffic signal, and automatically restart it again once the driver releases the brake pedal (or applies the acceleration pedal). This feature eliminates the wasted fuel of an idling gas engine, which causes overall mpg to climb significantly and tailpipe emissions to drop, especially in congested traffic situations. This process is virtually seamless, so much that the driver can barely feel (if at all) this whole process taking place. Automatic Start/Shutoff is the primary feature of Mild Hybrids

  4. Rechargeable Battery - Hybrid car batteries are commonly referred to as just “a battery”, however, they are actually a “battery pack” made up of many individual battery cells. The most common hybrid car battery is Lithium-Ion (same as used in cell phones), with other types including Nickel-Metal Hydride, Lead-Acid, and ultracapacitors. Hybrid car batteries are rechargeable, powerful, and typically last 10 years or about (or about 125,000 miles). With the exception of plug-in hybrids, the batteries are charged by 1) a generator powered by the combustion engine and 2) by regenerative braking. These batteries typically last Hybrid car batteries are sometimes criticized for their weight and pollution caused in either production or disposal.

Hybrid Car Categories

Parallel Hybrids
In a parallel hybrid, both the electric motor and combustion engine work together to power the vehicle. In most setups, the electric motor only provides an extra boost, and regenerative braking are the sole source of re-charging power for the battery. Parallel hybrids are often the simplest and least expensive type of hybrid technology. In addition, their preferential efficiency is achieved during highway driving at higher, more constant speeds.

Series Hybrids
In a series hybrid, only the electric motor is responsible for providing power to the wheels. The gasoline engine is not coupled to the wheels and does not provide power directly to the car. Instead, the gasoline engine powers the electric motor, which is charged by the battery pack or generator. A controller in the transmission determines how much power is needed to propel the vehicle and whether to pull it from the battery or the generator.

Full Hybrids
In a full hybrid, they can automatically choose to operate in series mode, parallel mode, or all-electric mode. They also have electric motors and batteries powerful enough to drive the vehicle, independently. This unique design makes them the most efficient hybrid among their fellow hybrid category siblings. The classic example of a full hybrid is the Toyota Prius, which has been in production since the 1990s.

Mild Hybrids
In a mild hybrid, the primary mode of propulsion is a gasoline-powered engine. An electric motor/generator operates in parallel, but will only kick in when the car needs additional power, such as during acceleration. The electric motor typically does not not have sufficient power to move the car by itself, and only assists the gasoline-powered engine (or allows it to switch off when the car is idling). This provides additional drive torque as well as regenerative braking.

Plugin Hybrids ( also called PEHVs)
In a plugin hybrid, there is a larger than normal high-capacity battery, thus, it can drive on electric power far further than other hybrids. PHEVs are defined as those solely driven by an electric motor for at least ten miles without consuming any gasoline and rechargeable batteries. Plugin hybrid batteries are recharged from public charging stations or a domestic power supply. Plugin hybrids can be driven by the motor and batteries alone, so they work more like conventional electric cars.

"Mini Hybrids"
In a mini hybrid, the vehicle uses only a small amount of electricity to help with its “Stop-Start" system. They are also referred to as an “eAssist system." Some automakers have intentionally avoided using the term "hybrid" with this system because it believes, that consumers have greater expectations for anything labeled "hybrid." They are not typically marketed as a hybrid vehicle. Because “mini hybrids” do not offer full hybrid capabilities, they can be built using very small and relatively inexpensive batteries to keep costs down.

Hybrid Car Pros and Cons


  • Efficiency - Hybrid cars achieve impressive gas mileage largely by switching from gasoline power to electric power whenever favorable, such as sitting still in heavy traffic. When an average gasoline powered car might achieve around 25MPG, its hybrid equivalent might achieve an impressive 50 MPG—approximately 100 percent better. This is because hybrid cars combine the benefits of both types of vehicles.

  • Economics - There are many economic benefits to hybrid cars. Some are purely monetary, like Federal Tax incentives or dealership rebates. Saving on refueling costs is another area of cost savings, since hybrids get almost double the gas mileage as purely gasoline fueled vehicles do. Lastly, as more people switch from gasoline or diesel cars to hybrids, hybrid vehicles will continue to hold their value as demand remains strong.

  • Environmental Benefits - While hybrid vehicles aren’t entirely emission free, they produce significantly less emissions than a purely gasoline powered engine. Combining an electric motor together with a gasoline powered engine creates better gas mileage, which means that less fuel is burned. Lesser fuel being burned means less pollutants entering the air. Lesser fuel being burned also reduces dependence on oil (both foreign and domestic).

  • Renewable Energy - Each time you apply brake while driving a hybrid vehicle helps you to recharge your battery a little. This process is called “regenerative braking,” and occurs where the electric motor applies resistance to the drivetrain causing the wheels to slow down. In return, the energy from the wheels turns the electric motor, which functions as a generator, converting energy normally wasted during coasting and braking into electricity. This energy is stored in a battery until needed by the electric motor.

  • Styling and Availability - As those in the market for a pure-electric or hydrogen powered car have experienced, the availability and styling choices are limited. In a report by J.D. Power and Associates “many car-buyers avoid green cars because they’re too small, look strange…..”. Fortunately, this is becoming an increasingly less important issue with hybrid cars. Many major vehicle manufacturers such as Honda, Ford, Toyota, GMC, and Chevrolet all produce readily available hybrid drive vehicles. In regards to styling, consumers even sometimes have the option to choose the same exact looking vehicle, in either a hybrid or non-hybrid model.


  • Price - Hybrid Cars are around 20–30 percent more expensive than a comparable gasoline model. High hybrid prices can be attributed to the fact that they come with costly high-voltage batteries and two engines on board. Normally, hybrid cars are priced about $5,000-$10,000 more than its equivalent with a purely gasoline only engine. Many price-conscious consumers are simply unable to afford the price difference in the two types of vehicles, regardless of savings incurred through better fuel efficiency of hybrid vehicles.

  • Maintenance Complications - While a hybrid car doesn't require significantly more maintenance than a gas-powered car, replacement parts made specifically for hybrid vehicles are not as commonly available and may be more expensive. Sourcing qualified mechanics to perform maintenance on hybrid drive technologies are also not universally available. The positive is that most hybrid cars come with extended powertrain and battery warranties. However, because hybrid vehicles weigh more, you can expect to replace tires more frequently as well.

  • Handling and Center of Gravity - Due to the added weight of the dual-propulsion systems, most hybrid cars are approximately 10% heavier. The extra weight is mitigated by lighter-duty components (not necessarily engineered for performance) and reduced bracing and support in the suspension and body. Additionally, hybrids are usually front-wheel drive, and the easiest and safest place for the batteries tend to be in the rear of the car. This distributes weight away from the drive wheels which tends to have a negative effect on performance.

  • Performance - Hybrid cars are built for economy, not for speed. The gasoline engine (which is the car's primary source of power) is much smaller than in comparable vehicles. If you need more acceleration than the conventional engine can provide, the electric motor assists in getting the car going. However, even with extra help, the total power output of the hybrid platform is often less than that of a comparable gas powered car.

  • High Voltage Safety - Some speculate that the high voltage electronic components found in hybrid vehicles, may pose potential safety problems during an accident. The electric components of the vehicle that allow it to be so fuel-efficient also mean that the engine has high-voltage wiring. This safety concern comes to light if the car is in a crash and some of these wires are exposed, emergency personnel or injured passengers to get in and out of the car, as they may be at risk of electrocution.