Working over 20 years Eaton has commercialized two distinctly different parallel hybrid systems that today are available through commercial truck and bus manufacturers worldwide. Each system significantly reduces vehicle fuel consumption and emissions output, and provide other benefits like reduced maintenance and brake replacements costs and noise reduction at work sites.

In general, electric hybrid systems have high energy storage capacity due to their battery pack and the release of energy from the battery can be slowed and easily controlled over time. Hydraulic hybrid systems can release power much quicker but for a shorter length of time before needing to be recharged.