Explain 'ICE high' mode?

[dalebunker]

I've heard mention a few times of ICE high (mode). Is this a setting, or a method of driving?

[oxnard]

Internal Combustion Engine

[zhackwyatt]

I've heard mention a few times of ICE high (mode). Is this a setting, or a method of driving?

It's a way of driving.  The idea is that at high speeds you want the battery fully charged so the Gas engine (the ICE) does nothing but propel the car forward.  When doing this I can get above 40mpg at 70mph.  If you drop down into EV mode, then when you get back up to speed, the car charges the battery with the ICE, getting you about 10-20 mpg while doing so.

 

My style of driving is basically, stay in EV mode as much as possible on surface streets (except I accelerate normally in Gas then switch to EV when I reach my desired speed) and stay out of EV as much as possible on the freeway.  This prevents my battery from draining requiring a recharge of it via the ICE.  On the surface streets, I get some battery back by Regen braking.  Also, on the surface streets, you can go much farther in EV mode than the it takes the distance to charge up the battery.

 

I'm struggling with how to explain this.  Let's say you start off with a nearly empty battery.  The car goes X miles on the surface street getting around 15 mpg charging that battery up.  After it reaches enough charge the car switches to EV mode.  The car can go farther in EV mode (N miles) than it took in charging up the battery to get into EV mode in the first place (i.e. N > X miles).

 

On the highway, it takes more energy to propel the car forward, so the difference between N and X is smaller and in some circumstances may even be reversed.  So the idea is to stop draining that battery and just let the ICE be as efficient as it can be at highway speeds.

[Jus-A-CMax]

I've heard mention a few times of ICE high (mode). Is this a setting, or a method of driving?

 

I coined the ICE High MPG (or mode) so let me explain this CMax phenomenon. 

 

In my view, its a bit of both but let me start from the start. The CMax we all know, 90% of owners, is either full EV or ICE so you're either doing great with 60+ blue MPGs or 15-20 white MPG when the ICE is on. However, what I noticed and someother too starting back when I joined this forum last Dec....is that the CMax really does amazing things when it has a really high battery. A high battery is either 90% or full. Now, this is not a normal battery state for the CMax unless you are doing down a long 5+ mile grade with brakes on (ala Box Canyon here in Los Angeles or Kanan Rd). 

 

When the battery is so high, the Ford engineers - in their wisdom - allowed the EV engine to assist the ICE. To see this, use the ENGAGE screen and you can see a blue and white power bars when you step on the accelerator with some decent battery.

 

Going back to your question - at 64mph or greater, we all know that the ICE is on full time. But what we didn't know or realize is that the Ford engineers allow the EV engine to "assist" the ICE even at this great speed. We are all told, anything more than 63 mph, you cannot drive full EV...but they did not say the EV could not assist. So, instead of poor ICE mulling along at 20MPGs all by itself, when the battery is high enough, the software allows the EV to assist in the propulsion of the car - this kicks in additional power and the instant MPGs goes to 40MPGs (thanks EV engine).

 

Then somehow or another (and this truly is a gray part of ICE High MPG), leave the engine and battery charging long enuf and you "double tap" the eco-cruise "-" at say 68mph, this will drop the speed a tad to about 66mph but it also then starts to dance the instant MPGs from 40 to between 40 and 60. I showed this photo today but I'll post it here:

 

 

This was taken on a flat 101 freeway, and you can see my eco-cruise on and the instant MPG.

 

Now - the easy way of doing ICE High MPG was attributed to "The Gen": I have found the illusive MPG sweet spot

 

You can do this manually as well by feather the pedal but I consider it more dangerous as your eyes are more on the gauge when they should be on the road. This was my original thread comparing the P&G, eco and ICE High MPG: Eco-cruise vs P&G vs ICE High MPG

 

I use both but more the Gen way, both have their merit. 

 

By the way, the ICE High MPG is good for flats only or downgrades. Going up steep hills or grades require additional power, which drains the battery back to a 50% state and you cannot run the ICE High MPG with this level. Do note that "The Gen" says to allow the eco-cruise to run for a few miles and this is because this allows the car to charge the battery up to the higher level.

 

I always said the secret sauce to the CMax is the high battery but its hard to get it up there and keep it there.

 

Hope this explains things... :)

 

PS zhackwyatt...good explanation too, didn't realize u posted as well  :rockon:

Edited April 17, 2013 by Jus-A-CMax

[wab]

Jus-A-CMax

 

How long does that +/- 50 "high instant MPG" last?

A couple of seconds, couple of miles  :drool: more?

 

How well do you think using "ICE High MPG" will preform on I 20 in west Texas (80 mph), I 70 in Utah (80 mph), Texas state highway 130 (85 mph).

I 20 and I 70 are flat, 130 some hills.

 

We drive all 3.

 

thanks

[Jus-A-CMax]

wab - the sweet spot appears to be between 65 and 70. It will last as long as the road stays flat (or at worst a wee bit upslope). We don't have those speed limits here in CA afaik, may be 70 for some stretch and I am relunctant to go at those speeds cause of CHP. Try it out at higher, worse you can do is 40MPG using eco-cruise and anything else is a bonus. The trick is the battery - keep that high, avoid the temptation of going full EV that sucks the batt. Give that Gen thread a good read - there may be some subtlety involved here with where to set the initial and then double tap down. 9/10 I would hit it, sometimes it doesn't -but the worse I've had is 40 and the best is a dancing instant MPG between 40 and 60.... :)

 

Let us know how you go with those higher speeds. :rockon:

[RachelnLa]

This makes me wanna hit the interstate.

[dalebunker]

Guys thanks for the great replies. You've confirmed one thing I'd noticed that when the battery is full, the instant mpg is higher. I know it not general practice any more, but I still warm up my car for a couple mins when I do this the battery tops off, before EV mode kicks in I see the average MPG above 40. Then on my way home today from Pleasanton( about a 30 mile run) I was late and ran between 70 and 80. I noticed the battery level was on average higher this less drag on the ICE when running at speed but not under a major load, again instant MPG above 40. So j agree a full battery = higher MpG. But takes some work to make it happen. But I understand the dynamics now, and hence can manage the results thank to you explanations !!

[Noah Harbinger]

My guess would be that the slight EV boost allows the ICE to run at its optimum RPM. 

[Adair]

wab - the sweet spot appears to be between 65 and 70. It will last as long as the road stays flat (or at worst a wee bit upslope). We don't have those speed limits here in CA afaik, may be 70 for some stretch and I am relunctant to go at those speeds cause of CHP. Try it out at higher, worse you can do is 40MPG using eco-cruise and anything else is a bonus. The trick is the battery - keep that high, avoid the temptation of going full EV that sucks the batt. Give that Gen thread a good read - there may be some subtlety involved here with where to set the initial and then double tap down. 9/10 I would hit it, sometimes it doesn't -but the worse I've had is 40 and the best is a dancing instant MPG between 40 and 60.... :)

 

Let us know how you go with those higher speeds. :rockon:

For my car it appears to be just under 70....68-69. I know when I find it, because the MPGs slowly begin to climb. Higher or lower and they drop.

[salsaguy]

does the cmax not show the mph set point you have it set to in cruise/eco cruise so you know your actual digital speed (in mph) and not just relying on an inaccurate gage/dial??

 

on my Passat i can see the cruise set speed as well as current speed

Edited May 31, 2013 by salsaguy

[Tdefny]

This is how the prius works. The battery is always in play somehow and allows the ICE to always operate in its best range for the given conditions. It is necessary to prevent the battery from going outside its safe range and is also defined by the relationship between the ICE, MG1, and MG2. Each has limitations on max RPM that define what must happen under various conditions.

 

The Max must be very similar because it uses the same principals. It seems to prefer all ICE or all EV, but can be coaxed into blending under the right conditions. I guess this is related to the bigger battery and bigger engine and perhaps different gearing.

 

Funny thing is that the procedure Jus' describes of setting the cruise and bumping it back two notches is how I always forced my Prius into stealth mode (at 42 MPH, its maximum).

 

I also find that a full battery does wonders for fuel economy. That is why I always plug my NRG in at night. (Sorry, I couldn't resist).

[zhackwyatt]

does the cmax not show the mph set point you have it set to in cruise/eco cruise so you know your actual digital speed (in mph) and not just relying on an inaccurate gage/dial??

 

on my Passat i can see the cruise set speed as well as current speed

No it does not unfortunately.  My parents 2011 Explorer Limited does however.  Not sure why they don't make things like that a little more consistent across vehicles.

[oxnard]

For my car it appears to be just under 70....68-69. I know when I find it, because the MPGs slowly begin to climb. Higher or lower and they drop.

My car likes 68-69 also.  But it is far better when battery is nearly charged.

[salsaguy]

jus - so how are you differentiating a speed difference between 67 mpg and 68 mpg for example if you don't see the actual speed on the gage/dial?

[Noah Harbinger]

jus - so how are you differentiating a speed difference between 67 mpg and 68 mpg for example if you don't see the actual speed on the gage/dial?

 

67.5 is exactly half way between 65 and 70, so it's just "Slightly more than halfway between 65 and 70", vs "Slightly less than halfway between 65 and 70". It's amazing how good we humans can get at differentiating such details, when we take the time to do so. 

Edited June 2, 2013 by Noah Harbinger

[salsaguy]

I know how to calculate the middle value but Im asking how he visually sees it on the dial since its not a digital readout and only a dial which can only be a guess/estimation since the markers are only every 5 mpg

[ScubaDadMiami]

What is the secret to getting the battery up to just the right level?  How long does it take to reach that level, assuming you started at about 35 percent?

[Noah Harbinger]

I know how to calculate the middle value but Im asking how he visually sees it on the dial since its not a digital readout and only a dial which can only be a guess/estimation since the markers are only every 5 mpg

 

I know what you're saying- I'm saying it's not hard to read it pretty accurately. But maybe I still have young eyes. 

[Adair]

I know what you're saying- I'm saying it's not hard to read it pretty accurately. But maybe I still have young eyes. 

 

Manners...... ;)

Edited June 3, 2013 by Adair

[frbill]

So Jus, I wonder if ICE High only works on flat roads. I never seem to be able to keep it in IH because in southern IL I am always climbing a hill.  I have tried to keep it in IH but on a hill the battery assist kicks in on a hill. I find that keeping at 55 I just get more consistently high MPG. Just wondering if I am missing something.

[fotomoto]

What is the secret to getting the battery up to just the right level?  How long does it take to reach that level, assuming you started at about 35 percent?

 

I haven't done enough hwy trips to get a firm handle on the distance but a guess is around 10 miles.    I do shorter, less than 5 mile legs daily and have recently found keeping speeds below 65 and P&G on EV delivers better mpg.  Need more tests though.

[Jus-A-CMax]

So Jus, I wonder if ICE High only works on flat roads. I never seem to be able to keep it in IH because in southern IL I am always climbing a hill.  I have tried to keep it in IH but on a hill the battery assist kicks in on a hill. I find that keeping at 55 I just get more consistently high MPG. Just wondering if I am missing something.

You are correct ice high mpg works on flats and some mild grades only. Any steeper grades/hills automatically draws too much power and kicks in 100% of ICE.

[nsteblay]

Image of C-Max HEV

 

https://docs.google....dit?usp=sharing

 

4 Modes of Operation

 

Series Mode

• Used only when vehicle is not moving and the engine is running
  
• Engine may be running for battery charging, cabin or battery temperature control, or catalyst warm-up.
  

Positive Split Mode

• Engine is ON and driving the generator motor to produce electricity
  
• Power from the engine is split between the direct path to the road and the path through the generator motor
  
• Generator power can flow to the battery or to the traction motor
  
• The traction motor can operate as a motor or a generator to make up the difference between the engine power and the desired power
  
• This is the preferred mode whenever the battery needs to be charged or when at moderate loads and low vehicle speeds
  

Negative Split Mode

• The engine is on and the generator motor consumes electrical energy to reduce engine speed
  
• The traction motor can operate as a motor or a generator to make up the difference between the engine power and the desired power
  
• Typical highway mode
  
• Occurs when the engine needs to be on, the system can not be operated in parallel mode and the battery is charged near its upper limit
  

Electric Mode

• The vehicle is propelled by stored electrical energy only
  
• The engine is turned off
  
• The tractive torque supplied from the traction motor
  
• Preferred mode whenever the desired power is low enough such that it can be produced more efficiently by electrical system than engine
  
• Preferred mode in reverse because the engine can not deliver reverse torque
  
• Separate electric pump maintains power assisted steering
  

The ICE High is Negative Split Mode.  These modes are described in the OBDII Theory and Operation available here.

[salsaguy]

i still think someone needs to do a YouTube video on the road to show us all how it's done.