ETorque adds up to better performance

by Jim KerrAuto Tech . Jan 04 2019
Fiat Chrysler AutomobilesThe 2019 Ram 1500 pickup incorporates the eTorque hybrid system, which means lower manufacturing costs and a bigger bang for the driver’s buck.

Fiat Chrysler Automobiles

The 2019 Ram 1500 pickup incorporates the eTorque hybrid system, which means lower manufacturing costs and a bigger bang for the driver’s buck.

The new 2019 Ram 1500 pickup has many new technologies, notably its eTorque mild hybrid system.

This hybrid system is used on both the 5.7-litre V-8 Hemi engine and their 3.6-litre Pentastar V-6 engine with some minor differences. With both engines, the system improves fuel economy, performance, load and towing capabilities.

Replacing the conventional alternator on the engine is a belt-driven motor generator unit, which performs several functions. It acts as a 48-volt generator, starts the engine when in automatic-start/stop operation mode, can provide additional power in some driving situations and provides regenerative braking during deceleration. The V-6 engine uses a liquid-cooled motor generator unit while the V-8 Hemi has an air-cooled unit mounted in the traditional alternator location. Another change is the addition of an accumulator to the eight-speed automatic transmission. This accumulator maintains oil pressure in the transmission when the engine is stopped in start/stop mode.

As a generator, the unit provides 48-volt power to a 12-cell, 430 watt-hour lithium-ion nickel manganese cobalt (NMC)-graphite battery located behind the rear seat. The small suitcase-sized battery pack contains a three-kilowatt DC-to-DC converter that provides 12-volt power to the Ram’s accessories and charges the conventional 12-volt battery under the hood. Two cooling fans inside the battery pack draw interior air across the battery to cool it and exhaust outside through the rear cabin vents.

Both the V-6 and V-8 engines use a conventional starter and 12-volt lead acid battery for initial starting of the engine rather than using the motor/generator unit. Once the engine is warm and operating in start/stop mode, starting is done by the motor generator unit. An eight-ribbed belt with dual tensioners to keep the belt tension in both start and generator mode turn the crankshaft to start the engine smoothly and instantly when the driver takes their foot off the brake pedal. The engine burns about two litres of fuel per hour while idling, so the start/stop mode helps increase fuel economy by about the amount of a cup of coffee per day. The 2019 Ram has up to 14 per cent better fuel economy in the city and a two per cent increase on the highway. Emissions are reduced by up to 10 per cent.

During driving, the system improves driveability. During the 3-4 shift in the eight-speed automatic transmission, the system slows the engine crankshaft for smoother shifts. During deceleration downshifts, the system is also programmed to aid in smoother shifts.

ETorque adds up to 90 ft.-lb. torque to the V6 engine and up to 130 lb.-ft. torque to the 5.7 L Hemi V-8 engine, helping increase towing capacity to 12,750 pounds — huge for a 1500-series pickup.

During deceleration, regenerative braking is provided by the system to recharge both the 48-volt and 12-volt batteries. Two electronic modules control the system operation and share 10 MB of software between the two modules. This is a very sophisticated system.

The eTorque system adds 90 pounds of weight to the vehicle but improves performance, fuel economy and driveability. It also paves the way for future vehicle electrical systems that will likely operate on 48 volts throughout the vehicle. It is a low-cost system to manufacture, and for the driver, it simply provides a big bang for the buck.

james.kerr@sasktel.net