Gas-sipping rental cars prove elusive.(Up front)(Brief article)

Remember when the offer of a bigger rental car was good news? Yesterday's upgrade is now considered a downgrade. Priceline.com found that 72 percent of 767 customers surveyed last year wanted more environmentally friendly vehicles--and that was when the price of gas averaged less than $3 a gallon. A Hertz spokeswoman cites a 40 percent increase in customer requests for hybrids and other fuel-efficient cars this year.

But there might not be enough to go around. At Hertz, hybrids make up 0.01 percent of the domestic fleet; Avis and its sister company Budget, 0.008 percent. Budget rents hybrids at about 115 of its 918 U.S. sites; Hertz, mainly at the nation's 50 busiest airports; and Avis, in nine areas outside California, where hybrids are most likely to be available.

We tried to book a hybrid vehicle in Los Angeles through six agencies. For a three-day rental three days in advance, only Alamo, Hertz, and National had a hybrid. For a booking two months ahead, those three and Avis had a hybrid. Budget was sold out in both cases, and an Enterprise agent told us hybrids can be requested but not guaranteed. ...