When the first hybrid cars hit showrooms roughly two decades ago, they were dismissed as science projects. But now hybrid powertrains can be found in everything from high-end supercars to humble taxis. Hybrids will become even more numerous over the next decade or so as automakers undertake ambitious electrification plans. But what is a hybrid car, and how does a hybrid powertrain work? We’ve got the answers, and a few tips for picking the best hybrid car for you.
What makes a hybrid a hybrid?
Merriam-Webster defines “hybrid” as “something (such as a power plant, vehicle, or electronic circuit) that has two different types of components performing essentially the same function.” In the case of a hybrid car, those components are an internal-combustion engine and at least one electric motor, both of which drive the wheels.
Better fuel economy is the primary motivation behind hybridization. The more you can rely on electricity, the less gasoline or diesel you need to burn. When the first mass-market hybrids — the Toyota Prius and Honda Insight — went on sale in Japan the late 1990s, most automakers felt all-electric cars weren’t practical because they couldn’t travel very far on a full charge. Hybrids were seen as a compromise between the efficiency of an all-electric car, and the practicality of a conventional gasoline or diesel car. While electric cars have improved significantly since then, hybrids still offer an environmentally friendly option for buyers in a more familiar package.
There are some side benefits, too. Electric motors deliver torque instantaneously, which helps cars pull away from a stop quicker. Companies are also finding that hybrids’ high-voltage electrical systems come in handy for powering the sensors and computers on self-driving cars. But fuel economy is still the number one priority.
Do you need a hybrid?
So you want to help save the planet, or maybe just save money on gas, but is a hybrid the right way to go? As with any car purchase, you need to consider your budget and needs and find a vehicle that fits them. But there are a few other things to think about when considering a hybrid.
If reducing pollution is your primary concern, you might be better off with all-electric car. A hybrid uses less gas than a conventional car, but an all-electric car uses none at all. But electric cars are still limited by range and lack of charging infrastructure in some areas, so they may not be a practical option for everyone. If you can’t guarantee access to a charging station, a hybrid may be the better option.
To get the most out of a hybrid, you’ll also have to consider how it will be driven. More so than other types of cars, the real-world fuel economy hybrids doesn’t always match up to the numbers on the window sticker. That’s because a hybrid’s ability to save fuel depends on the balance of internal-combustion and electric power, and that varies based on the design of the powertrain, and driving conditions. Hybrids generally tend to do better in stop-and-go city driving than highway cruising. Driving style can also have a big impact on fuel efficiency: Even a hybrid won’t get great gas mileage if you drive with a lead foot.
Finally, it’s important to note that not all hybrids are created equal. The “hybrid” label is an umbrella term that includes multiple subcategories, and some cars tick more than one of these boxes. Read on for a quick primer on the different types of hybrid powertrains.
As the name implies, mild hybrids are the least aggressive application of hybrid technology. They have electric motors, but these motors usually aren’t powerful enough to power a car entirely by themselves. Instead, mild-hybrid systems provide a small boost of power, or run a car’s electrical accessories to take some of the load off the engine. You wouldn’t mistake the 2019 Ram 1500 for a Prius, but Ram hopes a mild hybrid system will at least make it a bit more efficient than the average truck.
While they don’t decrease fuel consumption as much as more aggressive hybrid systems, mild hybrid systems are also cheaper, easier to integrate with a vehicle, and provide a driving experience that’s very similar to a regular gasoline or diesel car. That combination of factors means mild hybrids will likely be the most common type of hybrid on the road in years to come.
This is what most people are talking about when they say “hybrid.” It’s the type of hybrid system used by the Toyota Prius and dozens of competitors. Parallel hybrids can use an internal combustion engine, an electric motor, or a combination of both to power their wheels. That flexibility is key to allowing the Prius to achieve an EPA-estimated 56 mpg combined in its most fuel-efficient form.
Because they effectively have two powertrains, parallel hybrids are more complex than mild hybrids. But they return vastly better fuel economy, while providing a driving experience that’s still fairly similar to a conventional internal combustion car. The driver just keeps on driving while the car switches back and forth between fossil fuels and electricity.
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Like parallel hybrids, series hybrids have both an internal-combustion engine and an electric motor. But in series hybrids, only the electric motor directly powers the wheels. The internal combustion engine acts purely as a generator to charge the battery pack. This is probably the least common type of hybrid system at the moment. The Karma Revero is a series plug-in hybrid (see below), and Nissan has a series hybrid powertrain called e-Power. That’s only offered in Japan right now, but Nissan may bring it to the U.S. on Infiniti luxury models.
With only an electric motor propelling the car, series hybrids feel like electric cars from behind the wheel. Even when the engine is on, it can run more efficiently because it doesn’t have to match its revs with wheel speed. But the somewhat alien driving experience may put off some drivers.
A plug-in hybrid is exactly what the name suggests. It’s a hybrid that can be plugged into an external power source, like an electric car. In fact, plug-in hybrids are often lumped in with all-electric cars because they tend to appeal to the same group of environmentally conscious early adopters, and are tied into the same policy issues, like charging infrastructure and incentives. Plug-in hybrids qualify for a federal tax credit, and may qualify for state and local incentives, depending on the area.
Unlike other hybrids, plug-in hybrids can travel for relatively long distances purely on electric power. That’s because the ability to charge by plugging in allows for a bigger battery pack. The flipside is that you need to charge a plug-in hybrid regularly to get the full benefit. A plug-in hybrid that never gets plugged in is just another ordinary car.
This is a hybrid-specific kind of all-wheel drive system that uses internal combustion to power one set of wheels, and electric power for the other. This usually involves taking a front-wheel drive vehicle and adding an electric motor to the rear axle. That eliminates the need for a mechanical connection between the front and rear wheels, making it a straightforward way to add all-wheel drive to an existing hybrid system.
A hybrid car can be a great way to save money on gas, provided you pick the right one and have a good idea of how it will be used before you buy. With so many hybrids on the market, and more coming in the next few years, there is certainly no shortage of options.