Chrysler's Publicly-Funded Hydraulic Hybrid

When Chrysler let slip at the Detroit Auto Show that it would be offering a hybrid version of its 300 sedan by 2013, we automatically assumed that the Pentastar was going back to its Hemi-based Two-Mode V8 hybrid system, jointly developed by GM, Chrysler, BMW and Mercedes. Not so, it turns out. That billion-dollar drivetrain has been relegated to poor-selling hybrid SUVs, and it’s already being considered a dead-end by at least the German firms who helped develop it. Instead, it seems that Chrysler has gone to the government for a hybrid system, and will adapt a hydraulic hybrid system developed by the EPA.

The hydraulic hybrid system, developed by the EPA’s lab in Ann Arbor, is well known and currently used in industrial applications, including large delivery trucks and refuse trucks across the country. The technology has shown substantial increases in fuel economy when compared with traditional powertrains in the same type of vehicles. Working together, both parties hope to reduce the size and complexity of the hybrid system and produce a technology that is sensitive to the needs of drivers for smooth and quiet operation.

The research project will focus on adapting the hydraulic hybrid system to a Chrysler Town & Country minivan equipped with a 2.4-liter, inline four-cylinder gasoline engine. Components of the hydraulic hybrid system include a 117 cc engine pump, a 45 cc drive electric motor and a two-speed automatic transmission. Fluid for the system will be stored in a 14.4-gallon high pressure accumulator.

The system produces power with engine torque driving a hydraulic pump that charges the high pressure accumulator of up to 5,000 p.s.i. The high-pressure accumulator delivers the pressure energy to the axle hydraulic motor, giving the vehicle power to drive the wheels. The gas engine will remain off if the accumulator charge is sufficient to drive the motor.

The government may have failed to secure a meaningful green car commitment from Fiat when the Italian firm took Chrysler over, but by giving Chrysler access to its hydraulic hybrid technology, it may yet be able to generate some green headlines for America’s least-fuel-efficient automaker. And if $10m+ per-year EPA programs exist for anything, it’s surely to justify the green promises associated with the bailout. And, apparently, keeping Chrysler’s “World Engine” series somehow viable in the market.