Tacfoto
Posts: 29
Joined: Sun Mar 11, 2018 11:48 pm

Do the ECO Modes really extend the range?

Thu May 24, 2018 12:07 pm

I understand ECO Pro makes the car accelerate at a slower rate for a given push on the accelerator pedal. And ECO Pro+ probably does this more, AND it turns off any Climate control (but not the fan). Though 100% power and top speed seem unchanged.

But I can turn off the climate control, and I can accelerate the car slower, and limit my speed.

My question is do the ECO modes do anything I can't just do myself?

alohart
Posts: 1223
Joined: Sat Nov 01, 2014 7:36 pm
Location: Honolulu, HI

Re: Do the ECO Modes really extend the range?

Thu May 24, 2018 12:44 pm

Tacfoto wrote:My question is do the ECO modes do anything I can't just do myself?

I don't think so.

Some of us prefer the EcoPro/EcoPro+ power pedal mapping that makes it less sensitive in its initial travel but like full climate control power. In EcoPro, an iDrive setting allows one to decouple the climate control from EcoPro so that full climate control power is available in EcoPro (but not EcoPro+).
Aloha,
Art

2014 BMW i3 Arravani Grey, Giga World, Tech + Driving Assist, Parking Assist, DC Fast Charging, JuiceBox EVSE

jadnashuanh
Posts: 3881
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: Do the ECO Modes really extend the range?

Fri May 25, 2018 2:05 pm

A human may be able to replicate the general functions of the Eco modes, but he will not be able to do it as consistently. Depending on how conscientious you are at your efforts, you can approach that of the Eco modes, but would be unlikely to exceed them with a lot less stress and attention. While you may be able to turn off the HVAC, the computer also looks at the need for defrost, and will activate it before you may notice it is needed, providing a layer of safety. The same can be said (most of the time) for using the adaptive cruise control. It will notice the vehicle slowing down probably before you do and also return to set speed more economically. IMHO, though, that function doesn't work as great if you were not following someone, and come up upon a stopped vehicle...that decision/detection process slows the response down and can lead to a fairly abrupt stop, but it works pretty well if you were already following a vehicle in its sensor range. That's a disadvantage of a camera based system verses say LIDAR or radar which both would use more energy.
Jim DeBruycker
2011 535i x-drive GT, 2014 i3 BEV

Tacfoto
Posts: 29
Joined: Sun Mar 11, 2018 11:48 pm

Re: Do the ECO Modes really extend the range?

Sat May 26, 2018 5:00 pm

Jad,
The thing is, accelerating slowly is not really difficult to do in comfort mode. Turning off the AC, not difficult.

The computer looks for the need to defrost? Is that documented someplace? And of course it would need to find the need and then refuse due to the ECO mode. That seems unlikely.

One of the reasons I ask this is every few weeks I have to drive to a friends house and it's about 110 miles. Maybe 2/3 is freeway. My 2017 Rex turns on the Range extender with about 2-3 miles to go. I've run it in comfort mode with no A/C and I've run it in ECO Pro and Pro +. The battery runs out in the the same place each time, give or take 1/4 of mile or so. At the beginning of the trip Comfort predicts 99/100 miles of electric range. If I switch to ECO Pro+ the predicted range is as high as 145 miles. This is why I suspect the ECO modes are largely mental. You turn on ECO Pro + and drive slower. The slower driving saves energy.

jadnashuanh
Posts: 3881
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: Do the ECO Modes really extend the range?

Sun May 27, 2018 5:31 pm

The User's Manual describes what happens in each of the Eco modes.

Keep in mind that all range estimates are based on your previous driving. If you set a destination into the nav system, it will use that information to make an assessment of how far you'll be able to go. Keep in mind, otherwise, the car has no idea where you're going, the types of roads, the speed limits, or the terrain, so it uses the history data. If the original estimate was more economical than running long-distance down a highway at higher speeds, then yes, it won't be right. Also, at a steady speed, you're not accelerating or in regen much, so most of the energy use is drag and friction, again, not all that much an Eco mode can do. It's more likely to make a difference around the city in stop and go where you're starting/stopping much more frequently. Eco Pro makes it harder to go faster, but you still can. Drag goes up rapidly with speed.

Probably the biggest thing is that the computer is looking at conditions at least a few times a second...how often are you? Some are better at that than others.
Jim DeBruycker
2011 535i x-drive GT, 2014 i3 BEV

Tacfoto
Posts: 29
Joined: Sun Mar 11, 2018 11:48 pm

Re: Do the ECO Modes really extend the range?

Wed May 30, 2018 9:08 pm

OK so just for fun I drove the car around for a few minutes in Eco Pro+ with my fun pedal to the floor. Then switched to comfort and drove slow and conservative. Then, switching back and forth the car predicted 110 miles in Comfort and 96 in ECO pro! :D To me this confirms the modes are doing nothing I can't do with my right foot. Yes slower is more energy efficient, but it is just not hard to drive the car slow. I think this is a feature to make you feel good.

viking79
Posts: 74
Joined: Wed Apr 16, 2014 3:04 pm

Re: Do the ECO Modes really extend the range?

Thu May 31, 2018 3:08 am

This is my experience too, the modes are useful for helping to reduce climate power or make it easier to drive a certain way, but not necessary to achieve good efficiency. I find it easy enough to be efficient in comfort mode.

My 2015 Rex is showing 108 miles on the range indicator on a full charge right now. I only drive comfort mode. However, climate is generally turned off and mostly town driving. My last trip was 20 miles and 6.3 mi/kWh at 28 mph average.

It has been 90 F or more, in town I generally don't turn on AC until 95 F or other people are in the car, otherwise windows down. Highway is a different matter.

cdnji
Posts: 38
Joined: Mon Dec 12, 2016 2:07 pm
Location: Canada

Re: Do the ECO Modes really extend the range?

Thu May 31, 2018 11:30 am

I agree. The first few months, I enjoyed Comfort mode. Then winter came along and I happened upon the advice to use EcoPro to tame the acceleration a bit.

I figured that I should be able to do that myself in Comfort mode. But I still used EcoPro mainly for the Driving Style Analysis tool which gives a visual display of how efficient I drive.

At one point, I even considered coding my REx to "remember" the last mode set. Then I don't have to set EcoPro every time.

Once I consistently got 5 stars in EcoPro, I stopped using EcoPro. Last winter was my 2nd. I got through it using without switching to EcoPro. I still had to switch to DTC at times to deal with snow.
2017 i3Rex-Suite;Tech;Moonroof

jadnashuanh
Posts: 3881
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: Do the ECO Modes really extend the range?

Thu May 31, 2018 2:45 pm

Flooring the pedal overrides the eco mode so why would that be more economical than driving more conservatively?

To be fair, drive the same route as close to the same speeds as possible. Also, the range estimate won’t be a good estimate unless the conditions are identical which was not the case.

A better estimate would be to reset the miles/kwhr in between and compare those values. Faulty test procedures will produce faulty results.
Jim DeBruycker
2011 535i x-drive GT, 2014 i3 BEV

cdnji
Posts: 38
Joined: Mon Dec 12, 2016 2:07 pm
Location: Canada

Re: Do the ECO Modes really extend the range?

Fri Jun 01, 2018 9:29 am

I reset the km/kwhr to compare the values (also reset the other Onboard Info values at the same time). So I found out that yes, my stats improved. I used to do 19.7kw/100km on average. Using EcoPro learned habits, I now do 15.5 on average at Comfort mode.

Of course now, the total electric distance driven stat reported by the app - I use the Android iRemote (Canada) - now start from the point of reset, not from the time I registered the car.

To illustrate, the total distance as reported by the Odometer is 16K+ km. App reports 9K+ electric distance driven. I know that for the 16K+ km, I've used REx for probably 800km at most. But if I go by what the odo is saying and subtract what the app is saying, I used REx for 7K km.

So if the total electric distance stat reported by the app is important to you, you might want to think twice about resetting the Onboard Info.

EDIT: I meant 80km for the REx usage, not 800km.
2017 i3Rex-Suite;Tech;Moonroof

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