Slowing down the car a little can save fuel, but did you know that slowing an airplane a little can help too?

Drivers have long known that slowing down on the highway means getting more miles to the gallon. Now airlines are trying it, too — adding a few minutes to flights to save millions on fuel.

JetBlue adds an average of just under two minutes to each flight, and saves about $13.6 million a year in jet fuel. Adding just four minutes to its flights to and from Hawaii saves Northwest Airlines $600,000 a year on those flights alone.