Kayak.com, the travel website aggregator, has a new gas calculator in its car rental section so travelers can figure out the total cost of renting a car, not just the daily rates.
What's hot: Kayak's Fuel Cost Calculator considers a vehicle's mileage by using data from its manufacturer and info from FuelEconomy.gov. Input the miles you think you'll drive each day and it adjusts the cost of the daily rate in the search result. This feature is optional so you can look at the new cost and remove it with an "undo."
What's not: You don't see the cost calculator until after you have entered dates and location for your search. Once you get the results, you have to click on the fuel-cost link in the upper left navigation bar. And be warned: You could spend more time researching your car rental. Because Kayak also lets you compare prices across models, I got sucked into trying to figure out how much pricier it would be to rent a convertible instead of a full-size car during Labor Day weekend in San Francisco. The gas calculator told me it would be $15 a day cheaper to rent a convertible PT Cruiser from Thrifty than it would be to rent a full-size Chevy Impala from Enterprise.
-- Jen Leo