T+L puts airline booking sites to the test and finds the winners.

A study recently released by Consumer Reports' WebWatch tested 144 routes on 20 booking engines and found that European sites such as Travelprice.be often turn up lower fares than their U.S. counterparts.

We ran our own test, on 10 routes originating in the United States and between points in Europe, and our results were decidedly different. The major American-based sites (Expedia, Orbitz, and Travelocity) were the clear winners, sometimes beating their overseas competitors by hundreds of dollars.

One reason for this could be the ever-weakening dollar—the WebWatch tests were run almost a year ago. It also matters where your flight begins, according to Bill McGee, the WebWatch study's coordinator. American sites performed slightly better on routes originating in the United States and worse on routes within Europe. We found a few good prices on overseas sites for Euro- pean routes, but the savings were small. For example, Airstop.be beat Travelocity by $13 on a Copenhagen–London flight.

And there are two notable drawbacks to using European sites. Most of the non-U.K. sites aren't in English—so buying is a challenge unless you can read, say, Dutch. Also, many of these sites require a local address, even if you're buying an e-ticket.

Our advice?Stick to the U.S. sites or a travel agent for routes from this country. And for deals on intra-Europe tickets, you're best off booking directly from European low-cost carriers. Whichbudget.com lists them all by route; Applefares.com searches fares on seven budget airlines.