Can Cruise Control Save You Gas? Question Of The Day
Cruise control just might leave you with a little extra money in your pocket and fuel in your tank.
Photo by Nicholas A Tonelli / Flickr
Question: How much gas can be saved by using cruise control?
Answer: Unfortunately, there’s no definitive answer to this question. At best, a few scattered studies performed by auto-related organizations indicate that using cruise control correctly could boost gas mileage between 7 percent and 14 percent.
“There’s just not a lot of real-world data available,” says David Cooke, a vehicle analyst for the Union of Concerned Scientists.
On the other hand, we do know that the converse of using cruise control – aggressive driving at highway speeds, including rapid acceleration and braking – can decrease gas mileage by as much as 33 percent, according to the U.S. Department of Energy. So while it may not be exactly quantifiable, there’s definitely a benefit to using it, Cooke said.
Photo by Hector Alajandro / Flickr
Cruise control (invented in 1948 by engineer Ralph Teetor) saves gas because it essentially maintains a constant speed by adjusting the throttle position accordingly. Because it maintains a constant speed, the engine uses fuel much more efficiently than if speed up and slow down quickly, like these Furious 7.
“When you continually accelerate or decelerate – especially if you do it abruptly – you use more fuel than the engine’s combustion process requires, so the result is inefficient combustion,” Cooke said. “If you really stomp on the throttle (accelerator), you let in a lot of fuel – more than what can be combusted efficiently.”
Adaptive cruise control, which employs radar to automatically adjust a car’s speed to maintain a safe distance from any vehicles up ahead, also helps boost fuel economy.
“These systems look ahead, which is way more efficient than a bad driver who doesn’t look ahead,” Cooke said. “Adaptive cruise control decelerates and accelerates more gradually than the average driver, which makes the engine run more efficiently. You don’t lose any of the advantages of cruise control by using adaptive cruise control. In fact, it allows drivers to use cruise control in a wider range of traffic conditions.”
Photo by Ford Motor Co.
But cruise control isn’t always the most efficient way to drive. On flat terrain, yes – cruise to your heart’s content and figure out how to spend all that money you’re saving. On hilly roads, not so much. Why not? When you climb a hill while in cruise-control mode, your engine must rev up to provide enough power to maintain its speed. If required, it also will instruct the transmission to shift to a lower gear to produce higher rpms, which results in more fuel usage.
As common sense would dictate, it also doesn’t make sense to use cruise control in bad weather, amid heavy traffic or on twisting, winding roads. And if you’re tired, be wary; cruisin’ can easily lead to snoozin’.
If you really want to save gas, start your trip earlier and slow down. The Union of Concerned Scientists reports that setting your cruise control at 60 mph instead of 70 mph improves fuel efficiency by an average of 17.2 percent. And if you decrease from 75 to 55 mph, mileage increases 30.6 percent.
We’re scouring the Internet to uncover interesting questions that people have posted looking for advice from the unwashed masses. We will contact experts to give you well-researched, professional advice. You can also submit questions to autos_qotd@yahoo.com.
