General Motors and Honda led the light-electrification of the automotive industry with their respective mild hybrid drivetrains, but now that both automakers have abandoned the approach, competitors are adopting the technology in order to improve fuel economy. Fiat Chrysler Automobiles (FCA) is one of them, debuting its new eTorque mild hybrid system on the recently redesigned Jeep Wrangler and Ram 1500 pickup truck.
With the Jeep, eTorque is applied to the Wrangler’s optional turbocharged 2.0-liter 4-cylinder engine, where it helps to eliminate low-end lag for improved launch performance while enhancing fuel economy. With the Ram, eTorque is included with the standard 3.6-liter “Pentastar” V6 engine and is an option for the available 5.7-liter “Hemi” V8 engine.
Ram cites multiple goals with the technology, which adds 90 lb-ft of immediate torque with the V6 and up to 130 lb-ft with the V8:
- Improve fuel economy
- Boost performance
- Maximize towing and payload capability
- Enhance overall driveability
What is eTorque?
Essentially, eTorque is designed to lessen the load on an engine in order to make it more fuel-efficient.
Two components form the core of eTorque. The first is a belt-driven motor generator that replaces the traditional alternator. The second is a suitcase-sized lithium-ion battery pack.
The motor generator operates when the gas engine is running, delivering a 48-volt current to the battery, which converts it into 12-volt current to power the vehicle’s electrical accessories, and to keep the conventional 12-volt lead-acid battery topped off. When the vehicle is decelerating or braking, eTorque captures the energy produced by these actions, feeding it to the lithium-ion battery pack.
With eTorque, the engine’s automatic stop/start function can operate for longer periods of time, and under certain driving conditions and for short periods of time the mild hybrid system adds torque at the crankshaft for better performance. Similarly, during gear changes, eTorque adds torque at the crankshaft for smoother transmission shifting.
Real-World Fuel Economy with eTorque
To get first-hand experience with eTorque, I spent a week driving the redesigned 2019 Ram 1500.
My test truck had the optional 5.7-liter V8, which makes 395 horsepower and 410 lb-ft of torque. The V8 costs $1,395 extra and eTorque adds another $1,250 on top of that. In addition to the automatic engine stop/start system and available eTorque technology, the Hemi also has variable valve timing and cylinder deactivation.
So, how do these four fuel-saving systems perform when it comes to efficiency?
The EPA says that my test truck, a crew cab with four-wheel-drive, should’ve returned:
- 17 mpg in the city
- 22 mpg on the highway
- 19 mpg in combined driving
Without eTorque, the same Hemi-powered Ram is rated as follows:
- 15 mpg in the city
- 21 mpg on the highway
- 17 mpg in combined driving
During testing on my usual loop, which includes city driving, freeway driving, rural two-lane roads, and mountain switchbacks, the Ram 1500 eTorque returned 17.9 mpg with one person aboard and an optional tonneau cover over the 5-foot 7-inch cargo box.
While that result is further off from the EPA’s combined rating than it should be, I did have the truck in Auto 4WD mode, and not 2WD mode. I’ll also admit to exercising the Hemi with more enthusiasm than a typical government pencil pusher. This is a quick, satisfying truck to drive, and it sounds terrific when revved.
Are There Any Drawbacks to eTorque?
Since I didn’t compare a Ram 1500 V8 without eTorque to one with eTorque, I can’t comment on differences in driving dynamics. What I can say is that under normal driving conditions there is a subtle, momentary delay after you step on the accelerator pedal as the engine re-starts and supplies power. This, however, is normal with automatic engine stop/start systems, and the Ram’s engine re-start is relatively smooth.
Power off the line is robust, and if eTorque has a helping hand in that sensation, it is a welcome one. On a handful of occasions, though, such as when getting on the gas, lifting off for a moment, and then getting back on, I did experience some inconsistency in power delivery. Whether that had to do with eTorque or the transmission is unknown, and it didn’t happen consistently so I couldn’t purposely replicate the situation.
Given its general transparency to the driver, I’d say the main drawback to eTorque as applied to the V8 engine is the $1,250 cost of the technology.
In a country awash in cheap gas, it would take a long time to recoup even a part of that expense. And I’d bet that your typical Ram Hemi buyer isn’t exactly fretting about global warming.