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 estimates that, if produced, the ESX would cost $80,000. Most of the cost is from the exotic materials and electronic components.

The engine is 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 is powered by three engines. The first is a VM Motori S.p.A. 1.8-liter three-cylinder, turbocharged diesel, whose energy is diverted to an 180-pound, 300-volt battery and two oil-cooled electric wheel motors. The electric motors are also part of the regenerative braking system, where energy normally lost through the disc brakes recharges the motors.

The rear suspension, where the two 100-hp electric motors are located, is the semi-trailing arm type with coil-strut shocks. Panels are made of ultrathin-gauge aluminum, cutting the weight by 600 lb.. The controls for parking, reverse, and forward are 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 act as generators to recapture energy and convert 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 calls it a "mybrid" (mild hybrid) because its reliance on electrical power is not highly dependent on the battery. This system contains two motors that work in parallel: a 1.5 liter, 74-bhp direct-injection diesel and a 20-bhp AC induction electric motor. Coupled with the powertrains are a 5-speed electronically shifted manual transmission, a nickel-metal hydride battery pack, and controlling equipment which includes components from the Patriot hybrid race-car program.

The main power comes from the diesel engine. The electric motor charges the batteries, adds to the acceleration, and powers the reverse gear.

To cut down on cost and weight, Chrysler fit the car with a cheap, unpainted thermoplastic body attached to an aluminum frame. The shape has low aerodynamic drag. Inside, trim is constructed of carbon-fiber and seats are constructed from tube frame. The final cost: only $15,000 more than a regular Intrepid, or about $37,000.

Intrepid ESX-3

The ESX3 costs 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 combines a clean diesel engine, electric motor, and lithium-ion battery to achieve 72 miles per gallon (3.3 liters/100 km). That is 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) provides the fuel efficiency of a manual transmission with the convenience of an automatic.

The lightweight body uses injection-molded thermoplastic technology that cuts weight and cost. The ESX3 weighs 2,250 pounds (1020 kg) while meeting all federal safety standards. The vehicle is 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 have already been incorporated into other vehicles. The recently unveiled Dodge Durango hybrid prototype vehicle has 20 percent higher mileage. A thermoplastic hardtop will be available on the Jeep® Wrangler for the 2001 model year, while EMAT transmission technology is being developed for future production vehicles.