The claim. Tide Coldwater saves you "up to $65 a year," since you can wash in cold water, not warm.

The check. Our engineers crunched the numbers, using Procter & Gamble's footnoted assumptions: seven loads of laundry per week, a water heater set at 140º F, and 2007 national average electric rates.

CR's take. Cold is cool: You might save $65 a year, especially in an older, less-efficient washer. But hold on. With the qualifier "up to," the claim is valid even if you save a penny a year. Coldwater costs about the same as other Tides. For a report last January, we found the powder version worked very well in cold water. Like many detergents, Coldwater is being reformulated, but the energy savings should remain.