|"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 it predecessor, the
Dodge Intrepid ESX2," explained Tom Moore, Vice President - DaimlerChrysler Liberty
& Technical Affairs. "We also cut the cost penalty in half - from $15,000 down to
$7,500 - in two years."
Much of the driving pleasure is the result of ESX3's unique
EMAT transmission that 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
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.
(Feb. 22, 2000)