Please Explain ECO Mode - Gen III

ECO mainly adjusts pedal sensitivity, heat and AC output and engine shutdown at stops. Perfectly fine and recommended for most driving situations. Some don't like how cruise performs under ECO, but just experiment and find what settings work best for you and your husband! And enjoy the car!

 

I can assure you Toyota didn't put any button in the car which if pushed is "bad" for the car. Mine stays is ECO all of the time, since the weather has gotten colder, my mileage has dropped. You will see better mileage this summer, your doing just fine at 44.

 

Erikon gave you the correct answer. Seems to be especially useful in cold weather. I've never seen anyone say not to use it on the highway or with cruise control. There are some hypermilers that won't use cruise with or without eco, because they want to be able to glide above any preset limit. They all recommend using eco all the time though. Your husband may not like the throttle feel in eco, so just explain to him that you get used to that and that the throttle response is the same in all modes once you get past about the 50% mark. Just give it more gas if he wants more get up and go. Also, you don't have to be afraid of getting up to speed fairly briskly (actually, above speed and then ease off the pedal). The engine actually performs more efficiently that way.

 

There are a couple other threads related to this, my hypothesis is that PWR mode is better for hilly terrain, especially at highway speeds. ECO is probably better at lower speeds and flatter terrain. ECO may also be better in colder temps in stop&go driving (although grille blocking is worth a look in that case also).

Even better when using Cruise is to anticipate hills by accellerating a bit beforehand - that way the system doesn't have to play "catch-up" by pushing the engine near the red line.

 

As others have said the three driving modes, ECO, Normal (no button pushed), or PWR, change how the vehicle responds to the gas pedal during about the first half of pedal travel. For the second half of pedal travel they are all the same. In addition ECO operates the climate control system in a more economical manner. Note, I do not consider EV to be a normal driving mode and it should be used sparingly or not at all.

It's a matter of choice which of the driving modes you use, you should be able to get the same results from all three but your right foot may be in a slightly different position. I don't think the mode you are in has any effect on the cruise control at all.

I use ECO all the time because I like more precise control, especially while using regenerative braking. Think of ECO as fine control of the throttle, PWR as course control, and Normal between the other two.

 

I am in power mode 90% of the time, and I am at 42-44mpg because of the cold weather.

 

Coming from a normal car not long ago, I think the feel for traditional drivers is sort of like this:
PWR - feels fairly peppy/powerful, like a typical slightly-better-than-average midsize IMO.
Normal - a little more sluggish (particularly from full stops), especially if your previous car had a more sensitive throttle.
ECO - a lot more sluggish, unless (until) you're used to pushing the pedal fairly hard.

Pros/cons (IMO):
PWR - great for freeway onramps or jumping out into traffic (can be surprising). (Other modes seem to have more lag, even if you stomp them - as if it takes them a fraction of a second to come to that "not in Kansas anymore" realization.) Also good for hilly terrain. Not so good for "pulse & glide" since it's harder to "feather" the throttle, especially at slower speeds.
Normal - has to be pushed kind of hard to get strong accelleration.
ECO - better for "pulse & glide" and/or slower speeds and stop&go where you have plenty of time to get up to speed. Requires very firm inputs to get strong outputs.

Since a lot of my driving is in the "pulse&glide" zone (30-50mph), I'm playing around with ECO and simply putting my foot down hard when needed (like when starting from a full stop). Haven't tried to see what it takes to get that freeway-onramp accelleration when in ECO mode, but may get the opportunity at some point. The engine is broken in now, so I can stomp it if I want to

 

I always use ECO mode -- I like the fine control it gives me. At first it felt very unresponsive, especially when I first test drove the car, but I am 100% used to it now and the car feels great with plenty of acceleration.

What is hilarious is when I get into a rental car, especially a domestic. I had a Dodge Grand Caravan recently and I was really shocked when it took off like a bat out of hell with just slight accelerator application. LOL! Amazing how the human mind adapts.

They make most cars with overly sensitive pedals to make them "feel" fast.... On the rental, once you were passed the initial 1/4 of the pedal, there was hardly any difference between 1/4 and floored!

Anyway, this page describes it best: HSI

Specifically this picture:

 

LOL - After just 4 months with my Prius and now when I get back in my wife's Honda Accord, my wife and my son joke about whiplash from me taking off like a bat out of hell !!

 

LOL ... I bet if other car markers desensitized the throttle, it would help overall MPG. Of course, if Honda did this, for instance, people would complain the car feels "slow" etc ...

They should start adding a ECO button like the Prius that does the same thing -- lowers tip in sensitivity and makes the A/C run a bit less. (In Los Angeles, I had no problem with the A/C on ECO when I first bought the car in hot September)

 

I'm a real gear head and sports car fan ... but I'm a big-time geek too and that part of me won out when I was shopping for a new car. I love the Prius because it's so high tech and geeky! I love the HSI.

When I was shopping for a car, it cam down to 3 cars:

2006 BMW 335i (6-speed)
2010 Acura TSX (6-speed)
2010 Prius III

I bought the Prius. Super geek won out over performance.

My only complaint about the Prius is the plastic interior is noisy over bumpy LA roads. But that's for another forum......

 

I also live in Oregon the land of 10% Ethanol in your gas All Year Long. You will probably not get 50 real calculated MPG in the winter in Oregon. 44 MPG is about what we are getting here on the coast in Seaside in real world driving. I don't care what mode of power eco, ,norm, or power mode, you will not see 50 MPG's in normal winter driving, maybe with non-ethanol gas you would see about 48 MPG's. Or driivng on a flat dry road with no wind and at 45-50 mph you probably would get 50 mpg.

Remember that the Prius takes a bigger hit on MPG's than any other car in the U.S. from what I am seeing in this forum.


alfon

 

What I am finding is that there isn't much difference in MPG in the modes even if you accellerate differently - the computer is pretty smart and the system gets the best mileage after you're up to speed and coasting/cruising, and the energy it takes to get up to speed is roughly the same whether you spend it quickly or try to do it as slowly as possible. Hypermilers can probably squeeze out a few more mpg, but it takes a certain amount of "extraordinary measures".

The difference you're seeing from your husband's driving may be more about where he goes and what conditions (stop&go or whatever) he drives in.

44-45MPG winter is par for the course, from what I've read - and 55+ summer is probably par as well, so it nets out in the 48-50 range unless you do most of your miles in the winter.

 

Alfon and Prius4 (and anyone else within range) you might be interested in our HSD Meetup Group: The Portland Area HSD Meetup Group (Portland, OR) - Meetup.com

We meet one Saturday a month for lunch. Bill Merchant who is a member of this site is our organizer. We discuss hybrids, electric cars, etc. and compare Prius stories.

 

Thanks everyone for the posts on ECO mode. I had thought that switching between PWR and ECO caused some kind of fundamental change in how the HSD operates, but from what you're all saying, aside from heat/AC optimization, it's just about the relationship between my foot and the accelerator pedal. I think I'll leave it in ECO mode; my right ankle will be less confused that way. (Also, the greenie in me thinks that I SHOULD have to push the pedal down hard when I peel out from a stop -- helps me "feel" the CO2 plume billowing behind me...)