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What does "ECO" really do?

74K views 72 replies 30 participants last post by  JanP 
#1 ·
Really.

What does it physically do to the engine or transmission to improve economy?

Do you use it around town or only on the highway?
So far I've been switching it on when I get up to speed on the highway....but I doubt it's savings.....
 
#2 ·
I think it changes the shift points primarily. It may detune the motor somewhat.

I only use it around town when not in heavy traffic. It softens the throttle inputs, so I don't like it on in heavy traffic in case I have to scoot out of someones way. I don't think it does much in pure highway travel.

Oh yah, now BigSlick will come along and bust your balls for not using the search function. Ignore him, we do.
 
#3 ·
Thanks!

Ya, I'm aware of the search function......I've been around this "interweb" thing long enough... :p
I also figure that nobody asked questions, how would any new threads start - and therefore discussion would stop entirely.
Really, there is a limited amount of **** to talk about for cars and after a while it has to be repeated.......or people would stop coming to this website because it's dead.
This whole place could be just a search engine for Hyundai stuff - what's the fun in that?!? ;)

Ok, so I'm using the Eco for the wrong purpose.....I had begun to wonder if highway travel would make any difference at all with it.
I'll start using it around town.
 
#4 ·
it detunes the motor somewhat and i believe the shift points as well, as gixer stated. i dont know if it makes that much of a difference on the highway. i just leave it on.
 
#6 ·
It affects three thigns: the engine, transmission, and AC.

With the engine, it makes the acceleration smoother and more gradual.

With the transmission, it affects the shiftpoints, makes the engine go into a higher gear more quickly, and makes it less likely to downshift for power.

It also makes the AC a bit weaker.

On average, it's supposed to save you about 7% on fuel economy.

In real life, I've found it affects the feel of the pedal in a way I don't really like. With it off, it feels much more fun and peppy to drive. :)

Oh, it also helps train the driver to drive more economically. When you accelerate hard, the green ECO letters turn off, a way of letting you know that you're not driving as green as you could be. When you accelerate gradually, the green ECO letters stay on, a sort of thumbs up, telling you that you're doing your part to drive economically too. :)
 
#8 ·
starting mid model 2011, we no longer have the eco light. we have a dedicated button to turn on or off as we please.

i do agree tho, it kills the fun. pedal feel sucks and makes the car seem laggy.

EDIT: to my previous post, i leave the eco off. just caught that i said on.
 
#7 ·
Short shifting, lugging, make car less driveable... then people come in and complain that car not shift right or act odd...

I turn the ECO off, drive it, all is well, and give back with ECO turned off..

All it does is make the car less driver friendly in the name of "green".. the engine is still running, burning gasoline, spitting out the same tail pipe emmision either way.. Toss the ECO out the window and drive the car.
 
#14 ·
Judging by my Torque app (used as boost guage), it is much more hesitant to boost. Where as when you leave ECO off, boost comes on very easy; like almost any throttle input puts you into boost (hence the wastegate rattling at such low RPM's). The car will still fully boost under WOT, but it definately tames the turbo during part throttle driving.
 
#13 ·
Prenedo,

i do not notice any change in my AC but i can tell a difference in how the car performs which leads me to believe that it detunes it somewhat.
 
#16 · (Edited)
Works Ok. Wish I could monitor Knock and BAT's, but it gets boost and AFR (along with some other PIDs). I just bought an OBD2 bluetooth adapter (ELM is the brand) off of ebay for like 20 bucks. It was definately worth the money. It's cool, you can theme it, add different style guages (and different sizes), datalog, and a whole bunch of other stuff that I haven't messed with. Very similar to a dashhawk.

Here you go, same model number as mine. I swear these get cheaper by the minute... http://www.ebay.com/itm/Auto-Car-V1...509?pt=LH_DefaultDomain_0&hash=item19c9f612e5

I would love to know what is really being adjusted with ECO on. I'm gonna log boost, AFR and throttle input using ECO on and off and see if it's noticabely messing with those. One thing I was scared of when I first got this car, is that it leans out the AFR. I would guess that it does, but want to confirm that it isn't messing with open loop parameters (it could be dangerous if it is leaning out up top)...
 
#17 ·
Boost is a by product of your engine speed. If the engine is running at lower rpms so will your boost. The ECO adjust the shift points and throttle input. Thats all it has to do to increase mileage. Everything else is wives tales.
 
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#21 · (Edited)
Maybe its a difference between the 11 and 12. I sighted the page on mine and somehow on yours the word engine is switched with air conditioner? That makes no sense at all. Why would it control something that may not even be on all the time and then not say anything about the engine.

I have a feeling thats a typo in the 11 manual that they corrected in the 12 because it makes no sense.
 
#23 ·
Maybe its a difference between the 11 and 12. I sighted the page on mine and somehow on yours the word engine is switched with air conditioner? That makes no sense at all. Why would it control something that may not even be on all the time and then not say anything about the engine.
"engine, transaxle and air conditioner" - it's the very first word. If that's not saying something about the engine, I don't know what is.

Many vehicles have an "economy" mode setting on their a/c controls that changes how the compressor cycles. I see no reason to believe the ECO mode wouldn't have a similiar impact.

If that's misinformation, then so be it. I'm just stating the facts.
 
#22 ·
Wow.....see - if I had just of "searched" for this info then none of this talk would have been generated!

All in all.....I think I will drive with it on for the most part.
I don't need blistering hot starts off a light all the time. :p

Our cars are powerful yet I'm getting 32MPG on average and I only have 1700K on it. Woo-Hoo!!
 
#27 ·
OK, so here's the deal.

After reading the 2011 YF Turbo owners manual it seams they changed the operation for the 2012 model.

The 2011 models active ECO system does as Zebodog stated, it alters the operation of the engine, transaxle, and AC.

The 2012 model was changed to only control the engine and transaxle.

I apologize if it sounded like I came down on you Zebo but I guess we were both right.

I hope this clears things up for everyone.
 
#30 ·
If you want your Sonata 2.0T to feel and run like an Accent then by all means turn on the ECO but then you could have saved a whack of cash by buying the Accent in the first place. But good grief if you bought this race horse why would you turn it into a gelding.
The saving of 7% on gas is best case scenario, not worth it. If you're having trouble affording the extra gas then put the car on blocks or sell it...
 
#36 ·
I have driven 3 full fuel tanks with ECO off to test the perceptible differences.

My experience with ECO on (2011 2.0T) has been the following:

-Sluggish feel when using slight to moderate throttle and less downshifting when using slight to moderate throttle.
-In stop-and-go traffic and hot weather, A/C compressor will cut out intermittently (and more frequently.)
-Additional 2-3 MPG compared to ECO off.
-No perceptible change in performance at full throttle.

Based on my observations, ECO does exactly what the manual says it does.

I personally don't like the sluggish feel with ECO on, but for everyday commute I'd rather have the extra MPG.

Hal
 
#37 ·
Mine does the same but no change in AC. As revealed in the owners manual, it appears they took away the AC management in the 2012's.
 
#38 ·
I just filled my tank for the 2nd time. The first tank (from the dealer) was with ECO off. After I filled the tank the first time, I turned ECO on and committed myself to see how the drive-ability changed along with mileage.

The outcome = Like the others have said... I don't like the sluggishness of the car with ECO on. The change from first to second gear happens way too fast. My mileage was a little better by about 1/2 a mile per gallon. Definitely not worth the performance hit. I filled up today and turned the ECO off. The performance in city streets was much better.
 
#71 ·
You are probably hurting your fuel economy by popping it into neutral. Most modern cars shut off the fuel injectors when coasting in drive, but I don't think they do that in neutral.

I have an Accent, but I test drove the car with Eco on, turned it off, and NEVER used it again.

One thing Hyundai did right (and Toyota did wrong) is make the switch so that it constantly stays on unless you release it. The EPA has some rule that the car has to stay in the mode that you claimed the fuel economy in. On a Hyundai, you can use or disable Eco and it doesn't matter. On a Corolla S, you have a sport mode, but the car will start in normal mode and you have to enable sport mode every time you start the car if you want to use it.

(They are all shades of the same thing:
Eco mode - sluggish throttle response, faster upshifts into higher gears.
Normal mode - normal response, normal upshifts.
Sport mode - faster throttle response, later upshifts at higher RPM.
And typically, all of them are bypassed at WOT).
 
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