A Ram 1500 pickup truck is parked on a street.

What is a Mild Hybrid?

You’re probably familiar with hybrid cars, and have likely seen plenty of Prius models prowling the pavement. But have you heard of a mild hybrid?

While other automakers have responded to Toyota’s market-dominating Prius with standard and plug-in hybrid models, a little-known term — mild hybrid — is about to become big news. That’s because it describes models such as the 2019 Ram 1500, with more examples on the way.

A Hybrid Matter

Before we drill down into Ram’s new system, however, here’s a brief overview of the two most common hybrid technologies.

A conventional hybrid utilizes a gas engine and one or more electric motors, which are sometimes known as generators. Electric power comes from the motor and through kinetic energy from the brakes, which is then stored by a hybrid battery pack for later use. Hybrids alternate between gas and electric power sources or may use both concurrently.

A plug-in hybrid (PHEV) adds outside charging as another power source. As such, these models have larger battery packs and usually run on electric power only for 12 to 50 miles or more. Although PHEVs don’t require a full charge to operate, by connecting to a power source they’ll use less fuel. Both standard and plug-in hybrid models deliver exceptional fuel economy.

Although less widely known, it also isn’t unusual for automakers to incorporate hybrid technology in otherwise conventional cars, forming mild hybrid setups.

Chevy’s History With Mild Hybrids

2013 Chevy MalibuIn usages like the 2013 Chevrolet Malibu, a very small electric motor and a correspondingly small battery pack compliment the engine.

Chevrolet’s eAssist system shuts off fuel flow on deceleration, then activates the electric motor the moment you step on the gas pedal. It also has a stop-start function. Put these features together and you gain a more efficient powertrain.

Unlike conventional hybrids, these systems cannot power the vehicle alone — they must work with the gas-powered engine. Still, Chevy isn’t the only automaker to see their potential.

New Mild Hybrids Hitting the Market

Hybrid technology is constantly improving, and partial-hybrid systems are moving away from Chevy’s early examples. Although the components took up less space than conventional hybrids, the fuel economy gains were too small.

That’s changing as the all-new 2019 Ram 1500 pickup truck arrives. Ram, owned by Fiat Chrysler, is deploying a new eTorque mild hybrid system for the Ram 1500.

The Fiat Chrysler system, also used in the all-new Jeep Wrangler, replaces the traditional alternator with an electric motor generator unit (MGU). The immediate benefit is a huge boost in torque. A secondary benefit is an increase in fuel economy. The MGU also controls the engine’s start/stop feature, which shuts the engine off when idle, such as at a traffic light. When the driver lifts their foot from the pedal, the engine restarts. Yet another benefit is that the MGU powers the truck’s accessories. This means when the engine shuts down, the climate control system keeps running.

One of the key changes for this new breed of mild hybrid systems has everything to do with electricity — specifically, the voltage system in the car. Most models utilize 12-volt systems, but we’re now seeing the first 48-volt electrical systems.

As for maintenance, expect mild hybrid systems to mirror conventional models in service and durability. Follow the manufacturer’s maintenance schedule and take note of changes to the warranty, if any, should you buy one of these more efficient rides.

Check out all the electrical system products on NAPA Online or trust one of our 16,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on mild hybrids, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.

Photo courtesy of Flickr.

about author

Matthew C. Keegan

Matt Keegan has maintained his love for cars ever since his father taught him kicking tires can be one way to uncover a problem with a vehicle’s suspension system. He since moved on to learn a few things about coefficient of drag, G-forces, toe-heel shifting, and how to work the crazy infotainment system in some random weekly driver. Matt is a member of the Washington Automotive Press Association and is a contributor to various print and online media sources.

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