Why the Ramcharger was developed with a series hybrid powertrain, a pickup first

Stellantis will make a bit of history with the 2025 gasoline-electric Ram 1500 Ramcharger, the first series hybrid pickup marketed to consumers.

In a series hybrid, the gasoline engine has no mechanical connection to the wheels. Instead, the Ramcharger’s engine has just one purpose: To spin a generator that makes electricity that flows to the battery pack and to the front and rear electric traction motors that drive the truck.

The Ramcharger solves at least three major problems that have emerged at the start of the electric vehicle era:

  • It eliminates range anxiety. Ramcharger’s 27-gallon fuel tank and 92-kWh battery pack deliver an estimated 690-mile range. Refills of the fuel tank take just minutes.
  • It neutralizes owners’ concerns about the unreliable public charging network or the lack of chargers in rural areas.
  • It makes charging times irrelevant. Although the Ramcharger can be plugged in to bring the battery pack level up to deliver 141 miles before the gasoline engine kicks in, it is optional.

Battery-electric trucks from Rivian, Tesla, Ford and GM can’t match those traits. But the Ramcharger’s gasoline engine could be a nonstarter for consumers and businesses looking to go all-electric.

Also, as with any vehicle with an internal combustion engine, the Ramcharger will produce carbon dioxide, nitrogen oxides and other greenhouse gases. It will also need the same maintenance as a combustion-powered truck, such as oil changes and tuneups.


After testing competitors’ electric pickups, Stellantis engineers were convinced that a series hybrid powertrain would enable a Ram truck to deliver the towing and hauling capability and the driving range that many buyers expect in a pickup, regardless of powertrain.


Joe Tolkacz, Ramcharger propulsion system chief engineer, describes one of the tests: “We took one of our competitor’s trucks and loaded it up to their towing rate. Then we took it [from Stellantis headquarters in Auburn Hills, Mich., just north of Detroit] to Flint and back [about 76 miles] and we didn’t make it. We had to stop and charge. We said we really need to do something to extend the capability.”

It wasn’t a big leap, Tolkacz said, to create the series hybrid powertrain using many of the same components from the Ram 1500 REV electric pickup coming next year.

“We saw a lot of advantages. It was very tied to the use model for pickups. We think our customers are looking for a no-compromise truck. They like the idea of electric, and so this fit really well with that,” Tolkacz told Automotive News.

But the choice of a series hybrid powertrain is an unusual one.

Series hybrids with internal combustion engines spinning generators are common in diesel-electric locomotives but have rarely been used in automobiles. With pickups, automakers have used a variety of parallel hybrids, either mild or full, whose electric motors boost the gasoline engine.

Greg Davis, director of the Advanced Engine Research Laboratory and a professor of mechanical engineering, at Flint’s Kettering University — one of the nation’s largest automotive engineering schools — cites two reasons automakers have not installed a series hybrid in trucks: efficiency and cost.

“The downside is all the power from the engine has to go to generate electrons. It can’t be used to spin the wheels directly,” Davis said. “And so efficiency can take a little bit of a hit, especially at steady-state operation on the highway. Because if you have run down the battery pack, you are really just running the vehicle off the engine, converting all that mechanical power into electrical power and then converting back to mechanical power at the wheels. So, that’s a bit of a problem,” he added.


As for costs, because the Ramcharger relies on two powerful electric motors in the axles and a big battery pack, those components are far more expensive than what is needed for a parallel hybrid, Davis said.

“It was actually cheaper to do a parallel drive hybrid, particularly if you are doing a mild hybrid, where you are relying on the engine to provide mechanical power and only using the electric system to provide peak power. You can make the battery pack and the electric motor pretty small, so in many instances it’s a cheaper way to build the car, though it is more complicated to design.”


Tolkacz said his engineering team knew it had to make the Ramcharger drive like a regular truck — no easy feat when the engine’s power doesn’t flow through a transmission to the wheels.

“One of the criticisms of hybrids is that you’ll see engine speed flares and things like that,” Tolkacz said. “We developed a strategy so that when the driver tips in on the [accelerator] pedal, the engine operation is intuitive. You’ll see very typical operation. We have to balance that with efficiency, so it won’t be exactly like a diesel or a conventional gasoline engine, but it will be intuitive.”


Davis, who has built series hybrid powertrains, is intrigued by the Ramcharger. He said a pickup is a good application for the powertrain. The torque from the electric motors will make the Ramcharger’s acceleration feel a lot like that of high-performance electric car.

“It’s going to have a lot of torque off the line and then the engine can catch up,” Davis said. “You probably won’t feel the engine speeding up quite as fast because they can draw, for a limited amount of time, all the power they need right out of the battery pack. I think what you are going to find is that people will say, ‘Wow, this feels great,’ like the first time you get in a Tesla.”

Tolkacz describes the Ramcharger’s demeanor as extremely quiet and extremely quick. “Even when the engine kicks in, it’s really quiet,” he said. The 0-to-60 mph time, Stellantis said, is 4.4 seconds.


Stephanie Brinley, associate director of AutoIntelligence for S&P Global Mobility, believes Stellantis’ two-truck solution of the full-electric Ram pickup, the Ram 1500 REV and the Ramcharger, is a good strategy as buyers consider all the factors in making the move away from traditional gasoline and diesel pickup powertrains.


“Ramcharger has terrific potential to be an elegant and effective solution alongside the REV,” Brinley said in an e-mail. “Ramcharger has the potential to serve a wider range of use cases than the EV truck, and meeting a vast range of use cases is fundamental for full-size pickup trucks.”

Davis, looking at the published specs for the truck, said he believes Ramcharger could deliver eye-popping city fuel economy. Doing a quick back-of-the-napkin calculation, Davis said Ramcharger might get around 20.4 mpg at steady speeds on the highway.

That may not sound impressive when light-duty diesel trucks from General Motors and Ram have already crossed the 30 mpg highway threshold. But the Ramcharger, with its bidirectional charging, can power a house, recharge another EV and drive in areas where the charging network is not well established. Still, even with those attributes, Stellantis might have a challenge in marketing the Ramcharger.

“Pricing isn’t known yet, and that could limit accessibility in the first years,” Brinley said. “As with other new, electrified solutions, there is also room for skepticism. Ram will have to prove the solution out. The level of consumer education needed is high as well.”


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