The new Ram pickup truck can now be had as a mild hybrid. Standard on the base V-6 engine, and optional on the V-8, the eTorque technology comprises an electric motor/generator (EMG), a 48V battery and regenerative braking to keep the battery charged.
The intent seems obvious enough. With the EMG providing an electric boost, the gas engine doesn’t have to work so hard, and so it burns less fuel. A simple, elegant solution.
Except, it’s nowhere near that simple. After a test drive and a technical deep-dive, we’ve learned that the benefits of Ram’s eTorque technology are real enough, but how it gets there is vastly more subtle and multifaceted than you’d think.
It does save gas. Official numbers say the eTorque option on the 5.7-litre Hemi V-8 cuts city fuel consumption by 13 per cent – from 16.2 to 14.1 litres/100 km – compared with the 2019 model without it. Highway fuel consumption is marginally improved, while the combined number drops nine per cent, from 13.6 to 12.4 litres/100 km.
Official numbers for the V-6 haven’t been finalized, but over a 180-kilometre mostly gentle rural drive route, the trip computer in a V-6 Crew Cab 4x4 showed 10.6 litres/100 km.
The surprising part of the whole thing is that – despite the electric-motor torque ratings of 90 lb.-ft for the V-6 and 130 lb.-ft. on the V-8 – Ram is not claiming any acceleration gains.
Would drivers feel any difference?
“Some claim they do,” says Brian Spohn, vehicle electrification manager, powertrain engineering. “One of the things we had to overcome is the 90 pounds of vehicle mass added by these components, so we’d like to claim that although we added these parts, we didn’t slow you down.”
So if the EMG doesn’t directly power the Ram to any significant degree, what’s it good for? A lot of it has to do with optimizing and expanding the auto stop/start system that shuts down the engine to save gas when stopped in traffic.
“The engineering goal was to maintain no-compromise acceleration from an auto start so you are effectively not penalized because the engine turned off,” Spohn said.
The EMG can manage the shutdown more smoothly, while the 48V Li-ion battery can top up the 12V battery (yes there still is one) to enable longer shut-down periods of up to 10 minutes while still powering 12V cabin functions such as fan, audio, touch-screen etc.
Not forgetting, of course, that the 48V battery is usually charged “for free” through regenerative braking, instead of by an engine-driven alternator.
The EMG can also restart the engine faster than a conventional starter motor, and helps smoothly transition the engine back into drive mode.
Explains Spohn, “There is inherent lag to the engine being able to generate its own ability to move the product, so that’s where the [EMG] was optimized to be able to get that first half a rotation of the tire, ready for the engine to then take over.”
Bottom line, the EMG’s contribution to launch is very brief, and even if the driver is in a hurry, it’s all over by the time the engine reaches 1,200 rpm. “Besides, the 48V battery wouldn’t have the capacity to “drive” the truck for long: Its nominal capacity is only 430 Wh – about a third of the battery in a Toyota Prius, for example – and of that, Spohn says the useable capacity is only 130 Wh.”
Beyond the auto stop/start, eTorque saves fuel through the cumulative effect of numerous smaller techniques and optimizations – all masterminded by a huge amount of additional computing power. “It’s a smart decision process,” Spohn says. “Every five milliseconds we decide the next fate of the system.”
With the supporting role of the EMG, the gas engines can operate more often in their efficiency sweet spots. Running the V-8 more often in four-cylinder mode, for example, saves fuel when it’s working, but also reduces engine braking when coasting, so the regenerative braking can recuperate a greater share of the kinetic energy.
Under braking, to further maximize energy recuperation, the EMG can activate regen mode almost instantaneously, before the friction brakes have even responded to the pedal application.
The eTorque system even helps the eight-speed transmission work better: During upshifts, the EMG momentarily slows the engine, which makes the shift smoother, and in the process, it sends a little pulse of electrical energy back into the 48V battery. The EMG even helps extend transmission life, Spohn says, because it’s now doing work that was previously done within the transmission.
The V-6s aren’t in full production yet, but when they arrive, the eTorque will be standard. Pricing starts with the Tradesman Quad Cab 4x2 at an MSRP of $42,595.
The eTorque option on the 5.7 V-8 is available now, although only on the top trim levels, Longhorn and Limited Crew Cabs, starting at $66,295 (for a Longhorn Crew Cab 4x2). At that kind of money you’ll hardly notice the extra $500 for the eTorque option.