As prices at the pump relentlessly rise, RezHub.com and their Green Travel Hub offer travelers relief with the launch of a new and improved rental car engine, the company reports.

RezHub’s upgraded rental car booking engine allows customers to quickly and easily find and book with fuel-efficient and eco-friendly rental car options. The new booking engine actually highlights these "green" rental cars in the color green in the results of every search.

Green rental cars are classified by the Web site for falling into the hybrid, flex fuel or highly fuel efficient categories. Travelers will still be able to find the more standard booking categories like full-size, mini-van and SUV and no matter what is booked, RezHub will donate 20 percent of the proceeds to an environmental organization.

Also highlighted on the RezHub site are the economy and compact car classes which are typically the most fuel efficient rental car categories. RezHub has partnered with major national rental car brands such as The Hertz Corporation, Enterprise Rent A Car, Advantage Rent A Car, Ace Rent A Car and E-Z Rent A Car, to bring customers trusted results from reliable companies. The integration of the Enterprise and Advantage inventories are still in progress