Scoring frequent-flyer miles

FRESNO, Calif. (KFSN) -- Who doesn't want to fly for free? But can you really get where you want to go using your frequent-flyer miles? To find out, Consumer Reports asked staffers to try booking round-trip tickets using their frequent-flyer miles with nine programs: Alaska, American, Delta, Frontier, Jet Blue, Southwest, Spirit, United, and US Airways.

The staffers searched for a seat on the five most popular U.S. routes (Los Angeles to New York, Chicago to New York, Chicago to Los Angeles, Los Angeles to San Francisco, and Atlanta to New York) for flights that departed in three days, one month, and three months. The results were just a snapshot in time, but the options were often limited. Staffers had the most choices on Delta, followed by Southwest and US Airways.

The deals also vary widely. Spirit required the most miles for the routes staffers checked, followed by US Airways. And they both charged the highest booking fees: more than $100 for last-minute travel.

The best mileage deals were with Alaska Airlines, followed by JetBlue, American, and Delta.

And Consumer Reports found that you are usually far better off booking early. For example, on Southwest's Chicago to New York route, a round-trip ticket went from around 17,000 miles a month before departure to more than 77,000 for a flight three days away.

On short notice, United was the only airline that sometimes lowered the number of miles needed to book a seat.

Whatever you do, Consumer Reports says don't hoard frequent-flyer miles. You run the risk that they'll expire.

Consumer Reports says that if you can't book a seat using miles, try calling the frequent-flyer service desk. Agents can sometimes find seats that you can't.