In 1998, the Dodge ESX2 was introduced to high acclaim. For 2000, Dodge introduces a the next generation: the 2000 ESX3 Concept Vehicle.

In two years, DaimlerChrysler engineers have increased fuel efficiency to 72 miles per gallon (3.3 liters/100 km), improved acceleration and enhanced driveability - while cutting the cost penalty in half, from $15,000 over an Intrepid in 1998 to $7,500 over an Intrepid in 2000.

"A two-mile-per-gallon improvement might not sound like a huge engineering accomplishment, but this car also accelerates faster and provides a smoother, quieter ride while being less aerodynamic than its predecessor, the Dodge Intrepid ESX2," explained Tom Moore, Vice President - DaimlerChrysler Liberty & Technical Affairs. Admittedly, the ESX3 now looks less like a "high-mileage Electric Vehicle" than a normal combustion engined vehicle, which is a good thing.

Much of the driving pleasure is the result of ESX3's unique EMAT (Electro-Mechanical Automatic Transmission) combines two separate clutches in a computer-controlled, six-speed system that provides the shifting smoothness of an automatic transmission with the fuel efficiency of a manual. The EMAT transmission uses two clutches acting in tandem to provide seamless acceleration, with no torque interrupt during shifts. The typical manual transmission is 10 percent more fuel efficient than an automatic transmission.

"The EMAT is a vital link in helping us achieve up to 80 miles per gallon (2.9 liters/100 km)," said Tom Kizer, Director of Advanced Powertrain and Electrical Engineering at DaimlerChrysler Liberty. "All this technology is invisible to the driver, who sees the typical automatic transmission selections of Park, Reverse, Neutral and Drive."

The mybrid powertrain, consisting of a three-cylinder, 1.5 liter, all-aluminum direct-injected diesel engine and 15 kilowatt peak power electric motor, advances development of the powertrain in the ESX2.

As in the ESX2, the Dodge ESX3 mybrid powertrain reduces fuel energy use by only relying on the electric motor and battery to capture braking energy and reuse it to power accessories and provide a boost during hard acceleration. For additional fuel savings, the engine automatically shuts off when the vehicle is stopped, and the electric motor instantly restarts the engine when the accelerator pedal is pressed.

At 106 pounds (48 kg), the SAFT lithium-ion battery pack weighs less and is more compact than other battery options while providing more energy. The battery pack is fully integrated with cooling and control systems and is small enough to be installed between the rear seat and trunk, between the rear wheel housings. This provides ample cargo space of 16 cubic feet (450 liters) in the trunk.

Weight savings continue through the rest of the ESX3 powertrain - the engine weighs less than 250 pounds (113 kg), the air-cooled motor just 76 pounds (33 kg). In fact, the mybrid powertrain weighs less than a conventional powertrain that relies on only one combustion engine. In addition to the significant challenge of developing highly fuel efficient cars, PNGV engineers are also working on solutions to further reduce exhaust emissions. While the Dodge ESX3 meets the initial emission targets set by the Partnership in 1993, continued work on low-sulfur and synthetic fuels, new exhaust aftertreatment technologies and cleaner combustion processes is necessary to meet future standards.

Lightweight & Low Cost

The Dodge ESX3 concept car shows you don't have to sacrifice one to achieve another. At only 2,250 pounds (1020 kg), ESX3 takes advantage of DaimlerChrysler's unique injection-molded thermoplastic technology first shown in the fall of 1997 in the four-piece Composite Concept Vehicle (CCV). Keen observers will remember this Citroen "Deux Cheveux" look-alike as a potential 3rd World Country vehicle.

"The main structure of the Dodge ESX3 has only 12 pieces," said Bernard Robertson, Senior Vice President - Engineering Technologies and General Manager - Truck Operations, DaimlerChrysler. "That compares to up to 100 metal pieces in a conventional car.

"But the most impressive technical feat is that we've designed a lightweight body that would cost less than a conventional steel body - and much less than other lightweight material options such as aluminum, titanium or thermoset composites."

The low-cost, lightweight material also helps offset the weight and cost of the "mybrid" powertrain. The body system is estimated to weigh 46 percent less and cost 15 percent less to manufacture than a comparable metal body. A DaimlerChrysler patent is pending on the proprietary mix of thermoplastic, aluminum and lightweight structural foam from which the ESX3 body was designed. The one-of-a-kind concept car was actually built with hand-made thermoset materials that match the properties of the injection-molded thermoplastic design. A combination of aluminum, magnesium, steel and composites create the powertrain and chassis of the Dodge ESX3.

Computer-simulated crash tests show the Dodge ESX3 concept car stands up to all required federal tests. Data gained from actual crashes of CCV prototype vehicles, in temperatures varying from -40 to 210 degrees Fahrenheit (-40 to 100 degrees Celsius), help provide the necessary input to get accurate computer test results.

To give the body its strength, aluminum tubular sections are combined with the injection-molded thermoplastic body sections. This unique body structure is actually stiffer than today's Intrepid and will provide crisp ride and handling characteristics.

"We refer to the thin aluminum sections as the 'sparseframe' to distinguish it from currently available vehicles that simply hang plastic body panels over a conventional, metal spaceframe," explained Larry Oswald, Director - Advanced Body Engineering, DaimlerChrysler Liberty & Technical Affairs.

While the varying types of composites and plastics used in vehicles today are difficult to recycle, Oswald estimates at least 80 percent of the ESX3 could be recycled. That percentage could increase in the future as the market for recycled materials evolves.

Continued testing and improvements in generating a high-gloss surface color without conventional paint are required before complete vehicles are made with the thermoplastic material. DaimlerChrysler is first introducing this new technology on up to 5,000 Jeep® Wrangler hardtops for the 2001 model year.

On the inside of the Dodge ESX3, everything from the seats to the air conditioning system to the glass is optimized for lightweight, efficient performance. The concept uses several unique technologies to avoid temperature extremes so the heating, ventilation and air conditioning (HVAC) systems can run more efficiently. Solar reflective glass and paint reduce the amount of sunlight and heat that enters the car, so the air conditioning demands are reduced in the summer. The concept car also takes its own temperature when parked, and can turn the fan on to expel hot air and prevent the vehicle from ever reaching extreme temperatures.

Lightweight, aluminum-framed seats take passenger comfort to a new level by either heating or cooling the passenger through the bottom of the seat, as opposed to only blowing hot or cold air out of the instrument panel. Using a new electric heater design, the ventilation system can instantaneously provide heat on a cold day.

These energy-efficient technologies allow the complete HVAC system to be 40 percent lighter than in a conventional mid-size car. "We engineered every aspect of this car with efficiency in mind - and that includes cost efficiency," added Robertson.

Specifications

Body & DimensionsOverall length 192.8 "/4897 mm

Overall width 74.2 "/1885 mm

Overall height 55.3 "/1405 mm

Wheelbase 118.1 "/3000 mm

Front track 63.2 "/1605 mm

Rear track 63.2 "/1605 mm

Interior volume 102.6 cubic feet/2900 liters

Cargo volume 16 cubic feet/450 liters

Curb weight 2250 pounds/1020 kilograms

Coefficient of drag 0.22

PowertrainEngine 1.5-liter direct injection diesel

Material Aluminum block and cylinder heads

Peak power 55 kW (74 bhp)

Maximum engine speed 4200 rpm

Electric Motor/Generator Permanent magnet

Peak power 15 kW (20 bhp)

Maximum engine speed 4500 rpm

Batteries Lithium-ion

Pack voltage 165V

Peak Power 21 kW

Transmission EMAT - Electro Mechanical Automatic Transmission

Suspension McPherson strut in front, unique trailing arm suspension in the rear

Brakes Vacuum-assisted

Acceleration 0-60 mph 11 seconds (estimated)

Passengers 5

Recyclability 80 percent

Fuel tank capacity 6 gallons/23 liters

Range 400 miles/644 kilometers (estimated)

Fuel economy 72 mpg/3.3 liters/100 km (estimated combined city/highway, gasoline equivalent)

Fuel Zero sulfur, designer diesel

Emissions Meets initial PNGV targets (estimated)

HC - 0.125 gm per mile/0.078 gm per km

CO - 1.7 gm per mile/1.06 gm per km

NOx - 0.2 gm per mile/0.12 gm per km

PM - 0.04 gm per mile/0.025 gm per km

Cost Approximate $7,500 penalty over Dodge Intrepid price

SOURCE: Chrysler