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Does cruise control save fuel?

Is there a significant fuel savings when using cruise control or is it just a convenience.

For the average driver the answer is Yes. For those Hypermiler people they can beat it but who really wants to drive like that. The big advantage is it keeps people from creeping up in speed to where they might get a ticket and also reduce leg fatigue.


I think the savings are minor on average, not significant.

I agree, but for some people, the saving could be significant.
My crazy ex-boss liked to talk to his passengers, and for some bizarre reason, he thought that he should turn to look at the people to whom he was talking. In addition to the obvious safety problems of taking his eyes off the road every time that he turned his head, he also hit the brake. Then, he would look back at the road, and press hard on the gas to compensate for the loss of momentum from that unnecessary braking.

If he had used Cruise Control, and had to reactivate it every time that he hit the brake, maybe just maybe he might have figured out that he was killing his gas mileage (as well as his brake shoes) with all of that unnecessary braking.

Who knows? Maybe he would have learned to prefer the smoothness of Cruise Control to his annoying two-step approach to driving. Everyone in the office HATED to ride in his car.

What is “significant”? Cruise control might give you up to 10% better gas mileage but I doubt it’s good for more than that.

It depends. Nowadays, there is a variable on some of the cars that track the cars ahead, like Subaru Forester that brakes as soon as some one enters in the space ahead of you and if the distance is less than you have adjusted. So in Forester, we do not get better mileage
Older Sentra, we notice a slight improvement.

In theory, it should benefit but how much that depends on a ton of variables.

For good drivers the savings are miniscule. For lead foot drivers who constantly accelerate and then slow down the savings would be significant.

I only bought it to relieve leg fatigue on long trips on the large stretches of highway we have here.

It would save my wife a lot of fuel if she would use it. She treats the gas pedal like an on/off switch, speeding up behind the car ahead and then braking, then speeding up again…

Unfortunately, she refuses to use cruise control.

Off-topic - but don’t those adaptive cruise controls cause false alarms in radar detectors?

I have to agree it is more of a convenience but not a big thing either way. You get the best mileage on the highway with a constant setting on the accelerator. With cruise, it will be changing the throttle all the time to maintain a constant speed rather than a constant throttle. Of course a constant throttle means you will be slowing down and speeding up depending on the road and this will drive other people nuts as well as can create dangerous situations. So just use cruise and don’t worry about it.

On flat highways, the cruise control can generally beat me by about 1-1.5 MPG. On four lane roads (not interstate highways, but main roads that might have 55-60 MPH speed limits for the most part) that are connecting roads that don’t bypass towns like interstates do. I can easily beat the cruise control, particularly if there are fair amount of hills.

I agree hilly terrains are worse for cruise control. Iove to speed down the hill and cruise up the hill, not necessitating downshifting. I would guess maybe 2 mpg savings on the ups and downs vs cruise control. Not a lot, but I hypermile my Galaxy S8, 5 days usual battery life, others I know can barely make it a day, Saving pennies an obsession, I still pick one up if I see it on the ground.

I have an S8 as well. I can get a day out it at most. Probably could squeeze a few more hours out if it I turned on some of the power saving features. Per AccuBattery, the battery’s total capacity is now down to to 2744mAh down from 3000 mAh when new. I plan on holding on to it until the middle of next year, but I my end up replacing the battery before then.

The biggest power savings for a phone, if you do not need it, turn of wireless, bluetooth and location, kill or remove unneeded aps that run in the bakground, and NFC. I know people that think DRL eats gas, ridiculous in my book, ps AC on and windows open my pref, No Big Deal.

I believe CC saves fuel mostly due to speed limit discipline and that’s one reason I like to use it in my wife’s car. My car doesn’t have CC.
On hilly roads, I don’t use it because of the downshifts when going up hill. Without it, I can avoid the downshifts while only going a couple of mph slower up the same hill.
It’s also great for speed limit discipline in long speed zones, especially in New Mexico villages which often have miles long 25 mph zones on a road where you are the traffic. I’m talking about the village of Mora on state highway 518 in particular.

When I rent cars for vacation travel I try it both ways, and I tend to get better mpg on cruise control, but not much. When I drive across northern Nevada on I80, which is a constant repetition of long up-hills then long down-hills, I get the best mpg by using CC on the flat and downhill sections, and over-riding the CC when going uphill. Otherwise the CC will downshift to maintain the same speed going uphill and race the engine. I quite like the CC mode in general for long trips, not b/c of increased mpg so much, but that it makes the driving experience easier.

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I use wifi at work ( my office is located in the interior of the building, cell single won’t reach my office). I have a Samsung Gear S3 Frontier as my watch, so I need bluetooth on as well. NFC is off. I think that the phone is constantly searching for a cell signal, and that kills the battery life. I could put in airplane mode, but then I would have to remember to turn it off when I leave. I just live with it.