Cruise Control - Big Gas Saver?

[wabbit]

I haven't used cruise much in my 2010 3 GTS auto because I drive a little faster than most, and would be turning it on and off all the time. It seems like too much hassle.

Last week I made a 350 km trip on good highways that weren't too crowded, so I started using cruise. I have my readout set to show instantaneous fuel consumption and Km to empty. I quickly noticed that the instantaneous readout was showing lower fuel consumption peaks in traffic than when I drive without it.

My readout shows that if I used the full tank on this highway, I'd have got 720 km on the tank. That's higher than what I got on previous trips on the same highway.

You can't really compare two tanks of gas unless you're travelling the same route, week after week - which I don't. But it looks to me as though the cruise control keeps the speed more constant, which means there's less acceleration, and the difference in fuel consumption between steady speed and even mild acceleration is quite noticeable.

Has anyone noticed that using cruise gets better mileage?

[Fuyuzora]

... It looks to me as though the cruise control keeps the speed more constant, which means there's less acceleration, and the difference in fuel consumption between steady speed and even mild acceleration is quite noticeable.

This.

Although if your route is hilly at all, there's a good chance you'd be better off handling the gas pedal yourself.

I find using the cruise control leaves me a bit 'disconnected' from the car; but at the same time, it is nice when you're aiming for a consistent speed and good fuel economy. I also find I have an easier time resisting the urge to accelerate due to drivers up my rear when I have it set on cruise. :P

[peterm15]

i make the same highway trip almost on a daily, from 400-401 to 400-hwy 9. Driving at about 110km/h the fuel consumption is worse while useing cruise control.
I believe it is because of on the downhills the rpm's stay pretty regular even though the car feels like its coasting. When im not useing cruise control the rpm's lower slightly so it saves me gas. That trip is about 40km and driven at least 4 days a week.( there and back)

with cruise in a day ( from dupont and lansdowne to 9 and 27 and back, cruise on 400, 9 and 27) i get a combined fuel consumption of 8.6
without curise and the same trip ( aprox same outside temp) i get 7.9


i would assume on a pretty flat long trip that crusie would have better consumption.

[Booter22]

i have not noticed it as i also don’t use mine as much, i do remember finding some information where it says cruise will not decrease consumption but increase it because it will flux the gas pedal up and down to increase and maintain speed when going up an incline or less when on a decline vs loosing the speed and keeping your foot in one position to maintain the speed and coast when going down a hill. Also said it is better to have your windows open at 60km/h vs ac but close them and use ac around 100 km/h.

i suppose we will find out if we use our cruise more.

[pacmann33]

Cruise control is only good for fuel economy if you are driving on DEAD FLAT roads, otherwise...you're wasting gas. The best fuel economy comes from a steady foot, and a lot of concentration.

[cwp_sedan]

Cruise control is only good for fuel economy if you are driving on DEAD FLAT roads, otherwise...you're wasting gas. The best fuel economy comes from a steady foot, and a lot of concentration.

+1. I can get way better gas mileage without cruise, depending on the roads and traffic of course.

[The Wolf]

I save gas using CC but it's likely just due to setting it slower than I'd typically drive without it. Also, there's a few roads around me that are dead flat and have a 60km/h speed limit. I put it in 5th and set the cruise. There's no way I'd be able to keep my foot steady enough to match my car's computer. Also, my car's fuel consumption meter corroborates my story.

[sarujo]

I'm curious how many here that have cruise control also have a manual transmission. I just cannot imagine CC in a MT - thought it wasn't possible or even an option.

[crono06]

i have not noticed it as i also don’t use mine as much, i do remember finding some information where it says cruise will not decrease consumption but increase it because it will flux the gas pedal up and down to increase and maintain speed when going up an incline or less when on a decline vs loosing the speed and keeping your foot in one position to maintain the speed and coast when going down a hill. Also said it is better to have your windows open at 60km/h vs ac but close them and use ac around 100 km/h.

i suppose we will find out if we use our cruise more.

Lol yeah, I saw that on Myth Busters! I believe it is around 70km/h that you should close up the windows and use ac instead.

[CrystalWhiteGT]

I have to agree with the comments above. I drive 130KM min each day (65km each way). I find it's not so great on up/down hills. On a long drive, with relatively flat roads (I'm thinking a road trip), I think it would be very cost-effective to use cruise control.

[The Wolf]

I'm curious how many here that have cruise control also have a manual transmission. I just cannot imagine CC in a MT - thought it wasn't possible or even an option.

I have CC and MT.

[CrystalWhiteGT]

And yes Sarujo, you can have the cruise control option with a manual transmission. Definitely leaves you feeling "disconnected" from the road, like Fuyuzora had said earlier.

[sarujo]

I just cannot imagine driving a MT with CC. I mean, you still have to manually downshift etc so what's the point? CC seemed to be ok in my Dad's 06 Sonata with AT, but yeah, pretty dead driving and easier for a driver to lose focus on the road. I don't miss it in my GX.


And yes Sarujo, you can have the cruise control option with a manual transmission. Definitely leaves you feeling "disconnected" from the road, like Fuyuzora had said earlier.

[J.Dragan]

Yup cruise control and manual, 2010 Speed 3, I don't think I would buy a car without cruise.

[Fuyuzora]

I just cannot imagine driving a MT with CC. I mean, you still have to manually downshift etc so what's the point? CC seemed to be ok in my Dad's 06 Sonata with AT, but yeah, pretty dead driving and easier for a driver to lose focus on the road. I don't miss it in my GX.

As soon as you touch the clutch the cruise control disengages. Touching the accelerator will work as normal, but the CC remains engaged and will return to your set speed as soon as you release the accelerator.

It's really best for flat surfaces, which is the only place you really make gains anyway.

If you're on a long, relatively flat drive and you want to avoid the tendency to creep upward in speed it can be nice.

[Queue]

I've used the cruise control once in my MS3 just to see if it is functioning, then never used it again. I agree... feels too disconnected! It leaves me feeling like I'm doing something wrong. I need to know and feel that I have full control of the vehicle. Not sure how much it saves on gas, but I do believe in the steady foot. However, if I have an unbearable itch on my foot, cruise control could come in handy...

[S.F.W.]

If you're on a long, relatively flat drive and you want to avoid the tendency to creep upward in speed it can be nice.

Like a 4 hour drive to Ottawa ?

[Noisy Crow]

I just cannot imagine driving a MT with CC. I mean, you still have to manually downshift etc so what's the point?

On the flat highways in light traffic it works great. You rarely have to shift out of 5th. Parts of Hwy 400, not so great. But for travelling across the 401 or 407 it's fine. And I find that it does save me gas, as I just set it at 110, 115 and leave it there and take it easy...

[Fuyuzora]

Like a 4 hour drive to Ottawa ?

Haha, yup. If anyone wants to test it out there's a great opportunity to do so by travelling with you this weekend. :chuckle

Not so good on Hwy 17 though. :(

[Dreamliner]

I find it very uncomfortable and difficult to keep my foot steady enough to maintain one set speed for more than a few minutes (such as on a highway). I get the urge to speed up or end up slowing down. This is why cruise is so good for me.

[zmz3]

I find it very uncomfortable and difficult to keep my foot steady enough to maintain one set speed for more than a few minutes (such as on a highway). I get the urge to speed up or end up slowing down. This is why cruise is so good for me.

Same here.

I find my self trying to pass people, or switching lanes even.

[Scottobot]

I use it whenever I'm in light to no traffic in my Speed3. Whatever the fuel consumption it prevents me from going too fast and getting tickets. :)

[btown-mazda]

I tend to only use cruise control when taking long road trips. It really helps make the trip a bit bearable as I can stretch out my legs.

[slam525i]

CC in an MT works just like in AT, except the clutch has a CC cut-off, just like the brake does in an AT. It works fine. If anything, it holds better with less variation in engine revs (& throttle) due to the lack of a viscous coupling (torque converter).

Technically speaking, ideal fuel consumption comes from fixed throttle position. On, say the 401 east of 404 where it's flat, that means CC will do a better job than you can, since your foot can't really stay perfectly in position. However, on the DVP, for example, your foot might get you better fuel consumption as your will vary your throttle position less than in CC, allowing the car to gain speed on the downhill and lose speed on the up hill.

Me, I just leave CC on when the traffic is light. The fuel consumption difference is minimal. (If you simplify it down to an ideal system, the fuel consumption would be about the same as energy is conserved regardless. In fact, it would burn more fuel to allow the speed to change as you get increased air resistance at higher speed which is not equally compensated by the lower speed portions (resistance is proportional to speed^2), but in reality, engine inefficiencies make it better to hold the throttle constant.) My thinking is 1 speeding ticket is worth more than the gas I could save; Highway + manual throttle = too easy to speed.

(As a completely irrelevant side-note, ideally, you'd run wide open all the time (no throttle plate), and some how magically shrink your engine to change the power output. Your revs would be constantly at an ideal near red-line, held there by your magically shrinking engine which shrinks or expands to match changes in load. (The red-line wouldn't be what we have now.) Speed control would come thru an infinitely variable CVT (which also doesn't exist). I need to stop dreaming. and stop ranting.)

[hgmahaha]

Like a 4 hour drive to Ottawa ?

+1

or back to TO