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Wish the Hybrid had an EV mode


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With all the previous Prius and other hybrids I've driven prior to owning a C-Max, I always thought the EV Mode button was nice, but rather gimmicky. Tootling around a car park silently has it charms, for sure, but the limited range and speed in EV Mode in various Prii made it a bit useless.

 

Skip forward to now where I own a C-Max, and have it parked on the street. Thanks to alternate side street cleaning and limited parking spots in our area, I have to move the car a few times a week. Often it's just across the street, sometimes it's 10 car spaces away to make it easier for me to load or unload things from the car.

 

Sadly because there's no EV mode switch, the petrol engine will fire up to warm up the catalytic converter in anticipation of a trip I'll never make. Often I'll have 30-60% charge on my HVB, and leave the air conditioning off, but the engine will fire up anyway even with EV+ mode enabled.

 

I know there's nothing I can do about it, but I thought I'd cast this rant into the wind.

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16 hours ago, takingittothemax said:

... the petrol engine will fire up to ...

You assume the ICE starts right away for emissions reasons. My observations disagree. I've long been able to tool around the parking lot, and on cold start, at least to the mailbox (live in suburbs). 

 

Look for a reason the engine's starting. My money's on heat setting. Try turning environmental controls off and see if the ICE stays off. Not sure what else to lok for...

 

Stay well,

Frank

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1 hour ago, fbov said:

Look for a reason the engine's starting. My money's on heat setting. Try turning environmental controls off and see if the ICE stays off. Not sure what else to lok for...

 

I've been quite careful when moving the car to another parking space to make sure the heat/air con is switched off, ditto the seat heaters. Also been mindful to keep throttle inputs small.

 

Not sure what else it could be. Maybe the state of my 12V battery? An slight uphill incline?

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My understanding is that it's programmed to start to "prove" the engine and to warm up the catalytic converter.  Can you imagine a hybrid with an engine that won't start?

 

I did have one time very warm out with high SoC where I think it delayed engine start. 

 

The battery pack is very small in hybrid, it would work for your example but under normal conditions it would be depleted quickly.

 

Paul is very good at preserving MPG, I wonder how far he's been able to drive on EV?

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11 hours ago, jestevens said:

My understanding is that it's programmed to start to "prove" the engine and to warm up the catalytic converter.  Can you imagine a hybrid with an engine that won't start?

Before the car goes into ready to drive mode, all modules and systems are validated. Modules go through a self test / check which should pick up any anomalies which would prevent normal hybrid operation and if an anomaly were found, the car would not go into ready to drive mode.  ICE never starts immediately under “normal” conditions.  ICE starts when torque demand or other operator inputs exceed thresholds.  One can drive in EV quite a while on cold startup before ICE starts when higher SOC provided thresholds are not exceeded.  There may “extreme” conditions like low ECT, low ambient temp, max defrost / heat and so forth when ICE will start. 
 

When ICE does start and runs, the comprehensive emissions monitoring begins.  Here’s a copy of the latest I’ve found. There are many factors which the control algorithms will use to determine ICE on and ICE off / EV operations.

 

 

OBDSM1700_HEV.pdf

Edited by Plus 3 Golfer
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It doesn't start every time. I would say (off the top of my head), under 25-30% SOC it starts most of the time either when I turn the car on or when I very gently start moving.  Between 30-50% it may or may not start, but it does on occasion even when I'm super gentle on the throttle and don't have heat/air con on.

 

I don't think it's started over 50% unless I press the gas a bit too much. I don't usually have the battery at over 50% in my neighbourhood because I usually have to do one loop to find a decent parking spot, and it's over mile from the highway exit to my house with about 10 traffic lights or stop signs along the way.

 

I'm fairly sure it has to do with the slight incline I'm often parked on, and possibly the age of my 12V battery.

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On 7/1/2020 at 2:02 PM, takingittothemax said:

 

I've been quite careful when moving the car to another parking space to make sure the heat/air con is switched off, ditto the seat heaters. Also been mindful to keep throttle inputs small.

 

Not sure what else it could be. Maybe the state of my 12V battery? An slight uphill incline?

Put the Empower display up and see where the “EV off / ICE on” bar is.  The bar is generally a function of SOC of HVB (when in EV+ it moves higher).  Since the torque requirement should be small, the bar should be well above actual demand.

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10 hours ago, Plus 3 Golfer said:

Put the Empower display up and see where the “EV off / ICE on” bar is.

 

AHH! Thanks for that hot tip. Empower really does help. I can see the bar grow and shrink depending on the incline, and as the SOC changes.

 

After a bit of playing when I first bought the C-Max, I've left the display in Engage because I wanted to see how much power I was using from each motor.

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Yes, that display is very important to getting the best possible MPGs.  By lifting off the gas pedal carefully you can get the white column (on a curve) to drop off and for the blue column (battery power) to take over.  After a while you'll know how to minimize the ICE (gas engine) usage. Even a slight descent is often enough for the gas engine to stop and the battery to maintain the same speed.  I'm getting 52.3 mpg on the latest tank while my wife (who doesn't pay any attention to the display and runs the AC colder than I do) gets 45 mpg.  It always amazes me how I can be doing 45-50 mph and have the car regenerating power to the battery!  

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Yeah, I've been using the Engage gauge to do just that. My thing is to lift off on flat or declines if I'm going fast enough. The best I've managed is about 50mpg, and that was because there was traffic on the interstate. Most of the time I can only get between 43 and 48mpg on the highway because I can't resist going over 65mph.

 

 

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23 minutes ago, takingittothemax said:

... Most of the time I can only get between 43 and 48mpg on the highway because I can't resist going over 65mph.

If you're not familiar with the Advanced Vehicle Test facility...

https://avt.inl.gov/vehicle-button/2013-ford-c-max

 

This site has tons of data on hybrids and EVs through 2014, when Congress changed hands and funding was cut and testing was dropped mid-test. Thankfully, this was part of T=0 work.

Fuel Economy at Steady-State Speed, 0% Grade

15 mph 84.8 mpg

30 mph 80.1 mpg

45 mph 68.9 mpg

60 mph 50.3 mpg

75 mph 39.0 mpg

 

Now... I never got near these numbers; low 30's at best when driving on Eco cruise control, well below 75 mph. But it gives you an idea what's achievable. 

 

Stay well,

Frank

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4 hours ago, fbov said:

If you're not familiar with the Advanced Vehicle Test facility...

https://avt.inl.gov/vehicle-button/2013-ford-c-max

 

Wow. Interesting stuff that.

 

Yep. There's very definitely a sweet spot at around 50mph, and the few times I've been cruising at around that speed for a sustained period, I've my fuel economy improve markedly.

 

Sadly, it's hard enough cruising at the posted limit most of the time, and more so when the kids are in the back ready to be at the destination yesterday ?

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14 hours ago, fbov said:

If you're not familiar with the Advanced Vehicle Test facility...

https://avt.inl.gov/vehicle-button/2013-ford-c-max

 

This site has tons of data on hybrids and EVs through 2014, when Congress changed hands and funding was cut and testing was dropped mid-test. Thankfully, this was part of T=0 work.

Fuel Economy at Steady-State Speed, 0% Grade

15 mph 84.8 mpg

30 mph 80.1 mpg

45 mph 68.9 mpg

60 mph 50.3 mpg

75 mph 39.0 mpg

 

Now... I never got near these numbers; low 30's at best when driving on Eco cruise control, well below 75 mph. But it gives you an idea what's achievable. 

 

Stay well,

Frank

Unfortunately, those numbers used the incorrect RLHP coefficients when setting up the dynamometer.  At 75 mph I’m lucky to get 36 mpg with AC off.  Here’s my 2015 post on it.

 

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On 7/7/2020 at 3:22 PM, takingittothemax said:

Yeah, I've been using the Engage gauge to do just that. My thing is to lift off on flat or declines if I'm going fast enough. The best I've managed is about 50mpg, and that was because there was traffic on the interstate. Most of the time I can only get between 43 and 48mpg on the highway because I can't resist going over 65mph.

 

 

 

I'm in that same range of MPGs on long highway drives doing 70-75 mph w/AC - good to have some confirmation.  I often turn off the AC going uphill and re-engage it going downhill.  My wife thinks that's overkill but I do think it makes a difference.   Coasting does help too but there aren't that many situations where you can safely do that (read Paul Jones on the subject).  I keep the Michelins on both our C-Maxs at 50 lbs. as well. 

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Okay, we all like to hype our MPG at likely higher speeds than actual but we are talking about constant speed on flat ground (no hypermiling) per the INL tests.   The C-Max can not get 43 to 48 mpg (actual fuel burned over miles driven) at a constant speed of 72.5 mph (70-75 averaged).  On flat ground the C-Max will run in negative split mode virtually continuously at higher speeds which means ICE is on all the time.   Torque requirement don't change and HVB SOC is in the high 50% range continually.  When the 2013 C-Max first came out Cleanmpg tested it.  I've attached a graph of their data.   I have tested my C-Max FE many times over measured distances in both directions at constant speeds and generally get slightly higher numbers than the chart (but I run higher PSI.   Ford did add a few aero enhancements in later modes that would affect the numbers somewhat and increasing PSI in tires might add 1 mpg max. 

 

The INL FE data used RLHP coefficients that under stated the final 2014 RLHP by over 8% for speeds above 15 mph.  The effect on FE of the under stated numbers is seen in the EPA FE data.  Ford lowered the EPA (city, hwy, combined) FE numbers from 47/47/47 initially to 45/40/43 in 2013 and then to 42/37/40 in 2014.  So, the INL numbers are likely at least 2 mpg to high.   I have also attached the RLHP chart for the C-Max Hybrid for comparison on how the RLHP numbers changed with Ford's revisions.

 

 

 203496176_2013C-MaxFECleanmpgtests.JPG.6d4868b9c61f5ed4659b4703a84ced7e.JPG

1523252432_C-MaxRoadLoadHP.JPG.0c7e927ec08417e112fc07b69645d887.JPG

 

Edited by Plus 3 Golfer
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