In 1993, the Chrysler Corporation responded to a challenge by U.S. President Bill Clinton to produce a vehicle which was capable of meeting the demands of the modern consumer, while still achieving an unprecedented 80 miles per US gallon (2.9 L/100 km; 96 mpg-imp) overall in fuel economy. The PNGV - Partnership for a New Generation of Vehicles project was aimed at The Big Three American car manufacturers.

ESX I (1996)

The first attempt made by Chrysler at exceeding 80 mpg was designated the Intrepid ESX. The ESX I, although a series hybrid, used what might be considered "conventional technology". Chrysler invested an estimated US$3 million into the project, which used exotic materials in its construction: the model was priced at nearly $90,000; $70,000 more than the base Intrepid of the comparable year.

The engine was derived from a series hybrid-drive propulsion system meant to use 40% of gasoline's potential energy while at optimum RPM (the typical car only uses 15% of gasoline's potential energy due to wide ranges of RPMs). The car was powered by a VM Motori 1.8 L three-cylinder turbocharged diesel, whose energy was diverted to a 180 lb (82 kg), 300 V 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 batteries.