Priceline.com recently conducted a survey of its rental car customers and found that an overwhelming majority (72%) of travelers want rental car companies to offer economical, environmentally friendly hybrid vehicles powered by both gasoline and electricity.

A similar majority (71%) of the 764 priceline.com customers who answered the survey said they would rent a hybrid and almost half (48%) said they would be willing to pay a premium for their "green" rental.

While hybrid vehicles are generally not available through most rental car companies or through priceline.com, most of the priceline.com customers surveyed (39%) said they would be willing to pay up to $1 to $3 more a day to rent a hybrid.

Additionally, according to the company, eight percent of the priceline.com customers said they would be willing to pay up to $4 to $6 more a day for a hybrid.

One percent of customers said they would be willing to pay up to $7 to $10 a day more. No one was willing to pay more than $10 a day extra, while 53% of customers said they were not willing to pay any premium to rent a hybrid.

The already high and rising price of gasoline was another theme that turned up frequently in the new priceline.com survey:

· If gasoline reaches $3 a gallon, almost half (47%) of the priceline.com customers said they would change their rental car preferences and opt for smaller, more fuel-efficient car types.

· 55% of customers prefer to rent more fuel-efficient cars such as mid-size (example: Pontiac Grand Am), compact (example: Ford Focus) or economy (example: Chevrolet Metro).

· 96% of customers say they fill up their rental cars themselves before turning them in, rather than pay refill fees. 52% said they spend time looking for the cheapest gas in an area before filling up prior to return.