What Is A HEMI eTorque Engine And Which Pickup Trucks Have One Under The Hood?

What do the Toyota Prius, a Formula 1 car, and a 2024 Ram 1500 truck all have in common, other than four wheels? The answer is a hybrid system, although some might be more advanced than others. Of the three, Ram is the latest to the electrification game, only recently implementing hybrid technology into their trucks. Chrysler introduced their eTorque Mild Hybrid system in 2019 in select Ram and Jeep vehicles equipped with either the 5.7L HEMI V8 or the 3.6L Pentastar V6 engine. While the eTorque HEMI might be seen as blasphemous to some diehard Mopar enthusiasts, it introduces plenty of pros with very few cons.

The HEMI eTorque takes a simpler approach to hybrid implementation than most full-fledged hybrid vehicles on the streets today. The HEMI eTorque uses a motor-generator that is attached to the HEMI's crankshaft and expels energy to add additional torque during gear changes to make engine operation smoother, restart the engine during auto start-stop events, and even boost the engine's overall towing capabilities.

Unlike with electric vehicles, where a battery pack is charged through a traditional power source like a wall outlet, the eTorque's motor-generator charges a 48-volt, 0.4-kWh lithium-ion battery pack through energy recouped during braking. The entire system only adds 90 pounds to the vehicle's weight and is practically undetectable unless you know it's there.

The 5.7L HEMI is a tried and tested engine and has been a go-to powerhouse for muscle car and truck enthusiasts alike for over two decades. So, it makes sense that there are plenty of HEMI fans who view the eTorque HEMI with an "if it ain't broke, don't fix it" mentality. While there isn't anything wrong with the standard 5.7L HEMI, it's hard to argue that the eTorque version isn't worth it for the fuel savings, additional towing capabilities, and better overall drivability.

One of the main benefits that the HEMI eTorque touts over its standard counterpart is improved fuel economy. The HEMI eTorque gets an additional 2 MPG combined over the standard 5.7L HEMI in the Ram 1500, largely due to the eTorque's improved auto start-stop system. According to Car and Driver, a single 90-second auto stop-start event in the Hemi eTorque saves 1.7 ounces of gasoline, adding up to huge savings in the long run. The eTorque's motor-generator also makes the engine restart almost unnoticeable due to the fact that the engine is restarted directly from the crankshaft rather than from the starter battery.

In addition to the fuel savings, the eTorque motor also supplies supplemental power and torque to the engine. In total, the HEMI eTorque's motor-generator has an output of 16 horsepower and 49 lb-ft of torque. However, the torque is multiplied through the belt drive to the crankshaft, creating an actual assist of 130 lb-ft of torque. That additional torque can help get a sizable tow load moving from a standstill or simply provide more acceleration off the line.

The HEMI eTorque, which uses a 5.7L HEMI as the base power plant, has only been used in the Ram 1500 since its introduction in 2019. It was offered in most Ram 1500 trim levels as an optional package on top of the 5.7L HEMI, including the Limited, Limited Longhorn, Laramie, Bighorn, and Tradesman. With Chrysler announcing that the 2025 Ram 1500 won't have the 5.7L HEMI as an engine option, the 2024 Ram 1500 is the last model year that will have the HEMI eTorque under the hood.

While the Ram 1500 is the only truck to use the HEMI eTorque over the course of its production, other vehicles used eTorque in combination with other engine options. The 3.6L Pentastar V6 is another engine that got the eTorque treatment, which was also offered in the Ram 1500. The V6 eTorque, in addition to a 2.0L turbocharged 4-cylinder eTorque, was also available in the Jeep Wrangler.