Adobe.StockYou could save $250 in gas every year by doing just one thing.... "One of the best reasons for using cruise control right now, especially with high gas prices, is that it helps you keep and maintain a steady speed," said Mike Quincy, Auto expert for Consumer Reports. A steady speed can help you save gas. No speeding up quickly and then slamming on the brakes, just even, steady, consistent. Cruise control isn't just for road trips; it's for everyday use."As you're driving a steadier speed, your car is maximizing its fuel efficiency. You're not slowing down and speeding up all the time, and driving not erratically, but not consistently. So you want to improve your fuel economy, drive consistently," said Quincy. The sweet spot for maximum fuel efficiency is 55 mph. Consumer Reports tested it. Gas mileage at a steady 55 miles per hour versus 65 miles per hour and 75 miles per hour in both a standard car and a compact SUV.Testers found that when you reduced speed from 65 to 55 improved fuel economy by six miles per gallon in the car and eight miles per gallon in the SUV.AdvertisementAdvertisementIt seems everyone has tested this in some form or fashion. AAA estimates that driving consistently and smoothly can improve your vehicle's fuel economy by 10% to 40% in stop-and-go traffic and 15% to 30% on highwaysDOES YOUR CAR HAVE ADAPTIVE CRUISE CONTROL? USE IT IN STOP-AND-GO TRAFFIC"It worked perfectly for me, but I can understand some trepidation when owners try this for the first time because it's a little unnerving as your car is moving toward a car in front of you that's already stopped, and you think, ok, I hope it works. I hope it works. I hope it works. And then lo and behold, it works, and you can breathe a sigh of relief," said Mike Quincy, Consumer Reports Auto Expert. The Adaptive Cruise Control stop-and-go feature uses camera, radar, or a combination of both. Manufacturers may call it something different, so you need to check your owner's manual. AdvertisementAdvertisement"As you're experimenting with Adaptive Cruise Control, get an idea of what kind of gap length you want between you and the car in front of you, because it is adaptable. You can have a close gap, you can have a faraway gap. So you've got to do what works best for you," said Quincy. The Consumer Reports Auto Expert has it on his personal car and uses it often. Does your car have Adaptive Cruise Control? The best place is to look in your car manual. Manufacturers don't always call it the same thing.