Electrification -- the addition of batteries and electric motors to a car's powertrain -- isn't just a niche idea anymore. What started with the original Honda Insight and Toyota Prius has grown to include vehicles of all shapes and sizes, with myriad technologies on board predominantly centered around one goal: efficient, reduced-emissions driving. Unless you've got a million dollars for a hybrid hypercar, that is.
Hybrids and fully electric vehicles have a lot of other benefits, from federal, state and local tax incentives to increased HOV lane access. There are downsides, of course, like the potential for expensive (if rare) battery replacement costs.
With so many new types of electrified vehicles entering the market today, it's important to note the differences within this hugely important space. Below, we'll break out the different types of electrified vehicles on the market today, explain their advantages and disadvantages, and present examples of each.
A mild hybrid system is the simplest and most cost-effective way of adding electric drivetrain components to a vehicle powered by an internal combustion engine (ICE). In a mild hybrid system, the ICE will often shut itself off entirely under no-load conditions such as coasting down a hill or coming to a stop. The hybrid system allows the ICE to be restarted almost instantaneously and can power many ancillary systems on the vehicle like the stereo or air conditioning. Some mild hybrid systems will feature regenerative braking or will offer power-assist or torque-fill to the ICE, but all lack the ability to run solely on electric power.
- Can power many of a car's electrical systems.
- Stop-start system saves fuel during idle.
- Can reduce turbo lag by torque-filling until the engine comes on boost.
- Lighter weight compared to other electrified vehicles.
- Lower complexity.
- Lower cost.
- Increased cost and complexity versus internal combustion-only engines.
- No full-EV mode.
The series hybrid -- also known as power split or parallel hybrid -- is what most people think of when they think of a hybrid vehicle. These use a downsized ICE to provide power at higher speeds and in higher load conditions, and a battery-electric system to move the vehicle at low speeds and low-load conditions. This allows the ICE to work in its ideal efficiency range, thus providing excellent fuel economy, especially in city driving conditions.
- Excellent efficiency at around-town speeds.
- Gasoline-powered ICE for longer range (and longer journeys).
- Offers a good compromise between efficiency, usability and overall cost.
- Typically higher cost than a purely ICE-driven vehicle of the same size.
- Maximizing efficiency means reducing power output.
The plug-in hybrid is the next logical step forward from the series hybrid system. These cars move closer to the fully electric vehicle side of the continuum, with the ability to go longer distances on electric power alone. The plug-in part of their name comes from their ability to be plugged into an electric car charging station, rather than just relying on the ICE and regenerative braking for battery power, thus effectively eliminating range anxiety. Another area where plug-in hybrids differ from either mild hybrids or series hybrids is in the size of their battery pack. This is what gives them their extended EV-only range.
- Increased range over battery electric vehicles (BEVs) due to range-extending gasoline engine.
- Lower purchasing cost compared to BEVs.
- Lower running cost compared to series hybrids.
- More expensive to buy than series hybrids or mild hybrids.
- Larger battery packs mean more weight.
- More complex than mild hybrids.
Battery electric vehicles are mostly what they sound like: a big battery with at least one electric drive motor wired to it. Oh, and tons of incredibly complex software that's needed to manage the thousands of individual cells that make up that big battery. Mechanically speaking, BEVs are the least complex of all the vehicles we're covering when you consider that even the simplest multicylinder internal combustion engine has many hundreds of moving parts, while an electric motor only has its rotor. Purely electric vehicles are becoming more and more common, thanks to innovation from relatively new companies like Tesla and industry stalwarts like General Motors and Nissan.
- Mechanical simplicity means less maintenance than ICE.
- Tons of instant torque.
- Nearly silent operation.
- Electricity is cheap, for now.
- No tailpipe, therefore no emissions and no emissions testing.
- Low center of gravity is great for vehicle handling.
- More expensive than similar size series hybrids or ICE vehicles.
- Limited range.
- Lengthy charging times.
- Charging station infrastructure still up and coming.
- Impractical for most people unless you have 240-volt Level 2 charging at your home or parking spot.
- Higher weight than similarly sized vehicles.
- Uncertain environmental impact for end-of-life battery disposal.
Hydrogen fuel cell
A fuel cell takes hydrogen and oxidizes it to create an electrical charge, which is then channeled into a battery and used by electric motors. This technology has been around in automobiles for a few decades, but due to costs, size of components and a relative lack of infrastructure, there aren't many companies still working with it. Miniaturization of tech in the last few years has made hydrogen FCVs more commercially viable, and we're starting to see more interest from manufacturers like Honda and Hyundai.
- No need to charge; simply fill your car with hydrogen and go.
- Silent operation, much like a BEV.
- Only emission is water.
- Hydrogen prices fluctuate wildly, oftentimes more expensive than fossil fuels.
- Very limited refueling network outside of select cities like Los Angeles or San Francisco.
- Hydrogen tanks can eat into passenger compartment or cargo room if the vehicle wasn't designed from the ground up for fuel cells.