Research Project Information

Research Project Summary Information

Hydraulic Continuously Variable Transmission for Light Duty Trucks (ST9611-1)

Folsom Technologies International, LLC


Medium trucks (up to 14,000 lbs gross vehicle weight rating) are often used in applications requiring frequent starts and stops, such as is the case for trucks fitted with bodies designed for activities such as parcel delivery, refuse-collection and other specific functions. The frequent accelerations and decelerations often combined with significant idling time in traffic and while loading or unloading cargo can greatly increase fuel consumption relative to the amount of useful work accomplished. Greater efficiency can be achieved by replacing a conventional stepped-ratio transmission with a continuously variable transmission (CVT) that permits the engine to spend more time in its most efficient operating range. Also, during deceleration a conventional braking system dissipates the moving vehicle’s kinetic energy as heat that is wasted. A regenerative braking system can capture and store this kinetic energy for reuse during vehicle acceleration. Folsom Technologies International (FTI) has developed hydromechanical CVTs that transmit power using variable-stroke hydraulic pumps and motors. This approach, versus other CVT designs, can handle larger power levels within defined size and weight limits, and also provides the foundation for a hydraulic regenerative braking functionality.

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Project Description

This project was launched to develop powertrain technology that would apply the benefits of the above hydromechanical CVT and hydraulic regenerative braking to the medium truck market and other applications. The focus was on: (a) Preliminary design and performance estimates of a CVT suitable for installation in a Ford F350 truck, available with a gross vehicle weight rating (GVWR) in the Class 3 range (10,001 to 14,000 lbs) and powered by a diesel engine rated at 325 hp and 600 lb-ft (Model Year 2010), and (b) Integration of a CVT, dubbed “Next Generation” or “NG-CVT” and rated at 350 hp and 440 lb-ft, into a GM1500 pickup truck (i.e., General Motors Chevrolet Silverado, 7,300 lb maximum GVWR).


Incorporation of the hydraulic hybrid CVT should significantly reduce vehicle fuel consumption and associated emissions, especially in city driving. An additional benefit is reduced brake wear. Also, this new technology could provide the basis for a new manufacturing enterprise.

Project Results

The project yielded sufficient results for FTI to continue a working relationship with Ford and other interested parties, which may eventually yield a full commercialization effort.


Folsom Technologies International, LLC

Principle Investigator

Martin Hughes

Universities Involved


Project Type:

Product Development

Technologies Types:

Light Duty

NYSERDA Contact Information

Joseph Wagner


R&D -Transport & Power Systems

Contract Details

Start Date: 1/11/2010
Project Status: Active
Contract Number: ST9611-1

Last Updated: 2/4/2014 2