Jeep Grand Cherokee 4xe, electric beast
Available in the Grand Cherokee Limited, Trailhawk, Overland, Summit and Summit Reserve, the 4xe propulsion system combines two electric motors, a 400 volt battery pack, 2.0 litre turbocharged, four cylinder engine and TorqueFlite eight speed automatic transmission for maximum efficiency and capability. Overall, the 4xe system delivers 375 horsepower and 470 lb. ft. of torque. The Grand Cherokee 4xe, targeting an estimated 40 km (25 miles) of all electric range, returns an estimated 4.1 Le/100 km (57 MPGe) and has an estimated total range of more than 708 km (440 miles).
The fuel efficient 2.0 litre turbocharged I 4 engine is the high tech, direct injection engine that uses a twin scroll, low inertia turbocharger mounted directly to the cylinder head. Efficiency is enhanced via the use of electric power steering and an electrically driven air conditioning compressor, removing those loads from the engine. The conventional alternator is replaced with a high voltage, liquid cooled motor generator unit. Connected to the engine crankshaft pulley via a belt, the motor generator spins the engine for nearly seamless, fuel saving, start stop operation and generates electricity for the battery pack.
A larger high voltage motor generator is mounted in the transmission, replacing the torque converter. Two clutches manage power and torque from the e motor and engine. A clutch is mounted between the engine and the motor. When the system operates in electric only mode, this clutch is open so there is no mechanical linkage between the engine and the e motor. When the clutch is closed, combined torque from the 2.0 litre engine and the e motor flow through the automatic transmission. A variable clutch mounted behind the e motor manages engagement with the transmission to improve drivability and efficiency.
The Jeep Grand Cherokee 4xe carries a 400 volt, 17 kWh EV battery. The battery units and controls mount underneath the vehicle, packaged under the floor and protected by a series of skid plates. The battery pack system includes a dedicated heating and cooling circuit to keep the battery at its optimum temperature for best performance. The system includes a dedicated heater unit and a chiller that uses the Grand Cherokee’s air conditioning refrigerant to reduce coolant temperature when needed. ■