Hybrid ownership takes awhile to recoup purchase cost over a conventional car, but renting one can be profitable in a day.

Hertz announced today that it is putting 1,000 Toyota Prius gas-electric hybrids into its U.S. fleet this month. Avis said Wednesday that it will introduce 1,000 Priuses into its fleet by the end of this month.

Hertz, the largest rental company at airports, says a hybrid car costs renters $5 to $10 more per day. If a renter drives 500 miles, a hybrid car can save $20 to $45 in gas expenses vs. a standard vehicle, says Brian Kennedy, executive vice president of Avis
usatoday.com