Does Cruise Control Really save Gas?

[Shar]

Is the sole purpose of cruise control to help drivers relax their feet during long trips?

I question if cruise control saves gas because when I use it I can feel the throttle clicking on and off to maintain a specific speed. Wouldn't you save more gas but having a continuous throttle, rather than and on/off jerk?

 

[LargeCarManX2]

Only saves gas on flat road long trips.....

 

[Lethal1ty17]

the cruise control is only meant to maintain a constant speed. when used correctly i.e. flat, open highway with no obstructions, then yes it does generall save fuel because you wont be tempted to press the gas a little more to pass a car or truck. but its sole purpose is just to maintain speed, fuel savings is a nice side effect.

 

[oilboy123]

Really depends, with my Father it would save gas big time. Me not much at all.
He is all hyped up and all over the place on his speed, but I'm just the opposite. I do like it just to maintain speed when I have a little room. Helps me relax more and rests my feet.

 

[Shannow]

Cruise control costs me 10% easily in fuel.

I know what the road ahead is, and might give it a little more leading up to a hill, and let it lose a little more pace going up, knowing that I'm going to recover it on the other side.

Cruise control only reacts to speed.

 

[sciphi]

For the average driver who treats the gas pedal as an on-off switch it does save gas. It will modulate the throttle better on gently rolling terrain.

In hills it wastes gas since it tries to keep the car going at a constant speed up. That uses far more gas than going up the hill at a slightly slower speed that lets the engine run at a lower RPM.

There are folks whose right foot is a far better "terrain-adaptive cruise control" than any computer. Those folks are rare, though.

 

[JDD]

Generally, no. The only exception would be on long, very flat drives. Where cruise hurts MPG is on hills where it gets a heavy foot maintaining speed going up. If you are light on the gas pedal, you will drop some speed going up, but will keep the trans from downshifting and getting into the throttle and higher RPMs. Hypermilers don't use cruise in hilly areas, if at all and have this technique down. Same reason car manufacturers program their auto transmissions to not downshift until annoyingly late, which can be remedied with a reprogram of the computer on newer cars.

 

[crinkles]

not in my experience, I can't really tell the difference. It helps when you are doing 1000 km+ a day road trips to make you come out a bit fresher.

 

[Carbon]

Cruise control saves some of us from speeding tickets.

 

[rshunter]

Caterpillar had a cruise system for their on-highway engines that would mimic fuel saving techniques. It would allow a truck to lose a few MPH on climbs, and gain a few on hill descents. It achieved clearly measurable improvements in fuel efficiency.

 

[Shannow]

The system in the Audi hybrid concept car is great IMO, using GPS to map out the topography of the route would certainly make for a "smart" cruise control.

 

[Volvo_ST1]

Cruise control is useful when I have to look for something on the back seat, or if I want to take a nap.

 

[eljefino]

To read the service manual, cruise engagement means more TCC engagement. I wish this would work if it were merely switched "on" and not actively controlling speed.

I'm one of those pinheads who'll crest a hill at 10 under the limit if I know I'll pick it back up going down.

 

[Rick in PA]

Originally Posted By: rshunter
Caterpillar had a cruise system for their on-highway engines that would mimic fuel saving techniques. It would allow a truck to lose a few MPH on climbs, and gain a few on hill descents. It achieved clearly measurable improvements in fuel efficiency.


That's interesting. You would think auto manufacturers would offer dual mode cruise control, constant speed / max fuel economy.

 

[NHHEMI]

CC by itself doesn't do anything to save fuel but it can help people to do so for sure.

It definitely will save fuel for those drivers who are unconcious when it comes to their speed. You know, the people who are going 45 MPH in a 65 zone one second then 90 MPH two seconds later. They are all over the place because they are yakking on their cell phone or with their passenger and not concentrating on driving.

It also helps people who do not have a natural feel for speeds. What I mean is they start out at 60-65 MPH and plan to stay there but they kind of zone out after a while and slowly start to go faster and faster and before long they are at 75-80 MPH+ and don't know it.

CC will keep the vehile at whatever speed you wish +/- a MPH or 2 depending on terrain. I agree in extremely hilly regions it won't save fuel but for most folks it will even with a few hills to deal with. It does so by maintaining that steady speed with a much easier throttle than most people can do.

With that said you have to set it for a fuel efficient speed. Set CC at somewhere in the 55-65 MPH range and it will help your vehicle to achieve it's best highway MPG by removing your foot from the equation. Set it at 75 MPH+ and you obviously don't care about MPG so who cares what it does.

I actually use it in my vehicles at all speeds from 40 MPH and up. I get betetr MPG using it than when I try and do it myself. I am a conservative driver but even trying to drive easy the CC does a better job at it than I can.

 

[Craig in Canada]

Originally Posted By: Shar
Is the sole purpose of cruise control to help drivers relax their feet during long trips?

I question if cruise control saves gas because when I use it I can feel the throttle clicking on and off to maintain a specific speed. Wouldn't you save more gas but having a continuous throttle, rather than and on/off jerk?


As someone already said, if you're one of those drivers that exhibit poor throttle control, surging on and off the throttle even when you're trying to maintain speed on flat ground (I simply can't believe how many of these people are out there) then cruise control will save you money.

That being said, if you can feel the cruise control surging yours might need repair. Generally these systems are pretty smooth once up to speed and if yours is oscillating it certainly will not be saving fuel and part of your system might be sticking. I've never had a cruise control system "click on and off" when maintaining speed although I wasn't a driver when it first came out and when I seem to recall it was available in retro-fit kits.

Make, model, year?

 

[eljefino]

I got a kit from JC whitney for my 96 saturn SL. In hindsight I should have just gotten factory bits from the junkyard. Kit required vacuum for the actuator and had a three-position switch for power-to-weight. The best thing I can say for it is it functioned as designed.

 

[cchase]

I always lose a few mpg using cruise control. I find that it's too aggressive on uphill sections and doesn't let you recover any speed on the other side.

 

[bruno]

Definite gas saver . I installed an aftermarket cruise control on an old suburban that I used to drive from LA to Montana and there was a real improvement in mileage as well as being more comfortable to drive .

 

[Steve S]

Originally Posted By: Carbon
Cruise control saves some of us from speeding tickets.
That is a rather large savings!!