Chrysler Hybrid-Electric Cars of the 1990s: Dodge Intrepid ESX
Cautionary Note
Evan Boberg, in his book Common Sense Not Required: My Career With Chrysler, wrote that none of the hybrid vehicles described here lived up to the specifications given by Chrysler.
Intrepid ESX
The Intrepid was Chrysler's first attempt to exceed 80 mpg without losing space or acceleration. The total project cost $3 million to make, and Chrysler estimated that, if produced, the ESX would cost $80,000. Most of the cost was from the exotic materials and electronic components.
The engine was derived from a series hybrid-drive propulsion system meant to use 40% of gasoline's potential energy (the typical car only uses 15% of gasoline's potential energy). The car was powered by three engines. The first was a VM Motori S.p.A. 1.8-liter three-cylinder, turbocharged diesel, whose energy was diverted to an 180-pound, 300-volt battery and two oil-cooled electric wheel motors. The electric motors were also part of the regenerative braking system, where energy normally lost through the disc brakes recharged the motors.
The rear suspension, where the two 100-hp electric motors were located, was the semi-trailing arm type with coil-strut shocks. Panels were made of ultrathin-gauge aluminum, cutting the weight by 600 lb.. The controls for parking, reverse, and forward were located on the windshield wiper knob. The styling was incorporated in the 1998 Intrepid production car.
Specs: Dodge Intrepid ESX hybrid-electric car, 1997
- Vehicle: rear-engine, rear wheel drive, hybrid propulsion, 5 passenger, 4-door sedan
- Engine types: I-3 SOHC diesel, 2 valves/cylinder, with 2 electric wheel motors
- Regenerative braking (brakes acted as generators to recapture energy and converted it to electricity)
- Power: 75 bhp diesel + 2 x 100 hp electric motors = 275 bhp
- Torque: 135 lb-ft @ 2400 rpm
- Fully electric power steering
- Acceleration: 0-60 in 15 seconds (this was decreased in 1998 to around 9 seconds)
- Transmission: none
- Wheelbase: 113.0 in
- 600 Bolder Technologies spiral-wound lead-acid batteries producing 300 volts DC (180 lb), stored under the hood
- Length: 195.0 in
- Curb weight: 2880 lb
- Estimated 55 mpg
- Low emissions - below Tier 1
Specs: Dodge hybrid, 1998
- Same as above, except:
- Engine types: I-3 SOHC diesel, 2 valves/cylinder, with 2 electric wheel motors
- Power: 80 bhp diesel + 2 x 100 hp electric motors = 280 bhp
- Torque: 135 lb-ft @ 2400 rpm
- Acceleration (0-60): 9 sec (for 3.2-liter)
- Curb weight: 2880 lb
Dodge Intrepid ESX2
The second run was the ESX2, with a more modest goal of 70 mpg.
CC called it a "mybrid" (mild hybrid) because its reliance on electrical power was not highly dependent on the battery. This system contained two motors that worked in parallel: a 1.5 liter, 74-bhp direct-injection diesel and a 20-bhp AC induction electric motor. Coupled with the powertrains were a 5-speed electronically shifted manual transmission, a nickel-metal hydride battery pack, and controlling equipment which included components from the Patriot hybrid race-car program.
The main power came from the diesel engine. The electric motor charged the batteries, added to the acceleration, and powered the reverse gear.
To cut down on cost and weight, Chrysler fitted the car with a cheap, unpainted thermoplastic body attached to an aluminum frame. The shape had low aerodynamic drag. Inside, trim was constructed of carbon-fiber and seats were constructed from tube frame. The final cost: only $15,000 more than a regular Intrepid, or about $37,000.
Intrepid ESX-3
The ESX3 cost only about $7,500 more than a comparable gasoline-powered car, down from a $15,000 premium with the ESX2, and $60,000 with the ESX.
The ESX3's mild hybrid electric (or "mybrid") powertrain combined a clean diesel engine, electric motor, and lithium-ion battery to achieve 72 miles per gallon (3.3 liters/100 km). That was two miles per gallon better than the fuel efficiency of its predecessor, the ESX2 in 1998, and close to PNGV's goal of up to 80 mpg (2.9 liters/100 km).
A unique electro-mechanical automatic transmission (EMAT) provided the fuel efficiency of a manual transmission with the convenience of an automatic.
The lightweight body used injection-molded thermoplastic technology that cut weight and cost. The ESX3 weighs 2,250 pounds (1020 kg) while meeting all federal safety standards. The vehicle was more than 80 percent recyclable.
Rethinking the car's electronic and electrical systems cut several pounds from the weight of electronics while providing an ergonomic system of controls and indicators, high-performance audio and video systems, and a state-of-the-art telematics package.
Elements had already been incorporated into other vehicles. The recently unveiled Dodge Durango hybrid prototype vehicle had 20 percent higher mileage. A thermoplastic hardtop would be available on the Jeep® Wrangler for the 2001 model year, while EMAT transmission technology was being developed for future production vehicles.