Ford identifies error, lowers EPA fuel economy ratings for six vehicles

[salsaguy]

Agree. I think this is a very good way to alsoseparate themselves from the bad pr/press that GM has had with their key/ignition issue

Sad that the mpg for CMax is so low now but many here will be exceeding the numbers instead of being way under. Better to exceed expectations than under perform bit of course most still remember all those 47/47/47 commercials and will never give the CMax or Ford any chance to forget that fiasco  ;(

 

 

Still a great mpg car and still our top choice for now.

 

This however WILL result in even more lost sales to the crappy prii/prius for those that only buy based on mpg numbers alone and not ride/fit n finish quality which is more important than just mpgs to many.

This video for the announcement was on YouTube, and also on Facebook.  I commend Ford for at least stepping forward and taking responsibility.

The new combined mileage for Cmax of 40 makes my lifetime of 43.4 more impressive, and I know others have done much better than that.

Edited June 18, 2014 by salsaguy

[salsaguy]

What warranty plan/company are you all here considering using/getting for your CMax ?

With 63K miles already I think I will up the mileage on my 4y/100mi warranty if I get a check, YAHOO! Maybe they won't notice my 45.2mpg average.  :)  :happy feet:

 

Paul

[Testdriver]

I thought the 40/45 rating was accurate, but am happy to take Ford's money. I only averaged around 29 mpg during the worst Michigan winter in my lifetime, however, I get around 44 mpg during the summer. That's with about 80% city driving, mostly short trips.

 

Still a great mpg car and still or top choice for now.

 

This however WILL result in even more lost sales to the crappy prii/prius for those that only buy based on mpg numbers alone and not ride/fit n finish quality which is more important than just mpgs to many.

 

I agree with this. They're going to have trouble getting people into their showroom at the current MPG rating.

 

The C-Max will be due for a complete refresh in 2016 or 17, and it'll be interesting what Ford does with it, if anything. If they can pair their 1.0l 3-cyl ecoboost with an automatic tranny, then that engine is going to heavily cannibalize their hybrids. Why get a hybrid C-Max, when you can get the same car with more trunk space, similar performance and similar MPG for around $3000 less?

[SnowStorm]

I think the latest revised figures are now too low.  Future owners, unaware of the previous ratings, will experience the "under promise, over deliver" phenomenon and be very happy when they easily beat the new EPA numbers.

Then will Ford bring back the Lifetime screen?

[jennifermehl]

But the question is who gets the rebate--the original owner or you?

The Ford Customer Service representative verified my address and said the 2nd goodwill check would be sent to me.  I don't think the previous owner ever got the 1st goodwill check, but she said that the program was closed and they wouldn't be able to send that one to me (OK since I wasn't the owner when that program came out.)

[kostby]

To no one in particular:

If you're completely satisfied with your MPG's, and honestly believe that the Ford check could do more good elsewhere, you should pass the money on to one or more of your favorite charities.

 

Then it becomes a win-win: An unexpected bonus check for you can go where you designate it, to help the causes you're passionate about.

Edited June 16, 2014 by kostby

[ptjones]

I thought the 40/45 rating was accurate, but am happy to take Ford's money. I only averaged around 29 mpg during the worst Michigan winter in my lifetime, however, I get around 44 mpg during the summer. That's with about 80% city driving, mostly short trips.

 

 

I agree with this. They're going to have trouble getting people into their showroom at the current MPG rating.

 

The C-Max will be due for a complete refresh in 2016 or 17, and it'll be interesting what Ford does with it, if anything. If they can pair their 1.0l 3-cyl ecoboost with an automatic tranny, then that engine is going to heavily cannibalize their hybrids. Why get a hybrid C-Max, when you can get the same car with more trunk space, similar performance and similar MPG for around $3000 less?

You are going to be hard pressed to come close to Hybrid City mileage and they keep improving on battery technology. The next gen battery will have the same size and we will be able to go ten miles instead of 2.

Winter MPG's can be greatly improved(40's mpg's) by using Grill Covers, Oil Pan and block heaters as well as using seat heaters instead of ICE heater from the testing I have done. :) 

 

Paul 

[Jus-A-CMax]

Follow what Paul says, those grill covers work - ABLIET - don't climb long grades with them, even if it si 28F outside...I can hear Paul tapping his keyboard - there goes that whack grade climbing nut job again.... :sos:

[obob]

Follow what Paul says, those grill covers work - ABLIET - don't climb long grades with them, even if it si 28F outside...I can hear Paul tapping his keyboard - there goes that whack grade climbing nut job again.... :sos:

I am interested in the power that was needed as seen on the empower screen, like the number of bars, that make the engine temp rise.  Thanks.

Edited June 17, 2014 by obob

[ptjones]

I am interested in the power that was needed as seen on the empower screen, like the number of bars, that make the engine temp rise.  Thanks.

From the testing I have done temps go up when using more than 2 bars for a extended period of time. FMT (from my testing) you can leave the center cover on all time just remove the lower one when climbing for an extended period on time. FWY gas mileage is effected by not reaching optimum operating temps above 202*F, Grill Covers speed up the heating and improve the aerodynamics for about 2mpg. Jus try driving with center cover on and remove lower cover up your long grades up to Manmoth and see what happens. :) 

 

Paul

[plus 3 golfer]

As I've posted in another thread I've done coast down tests on the C-Max over the past year and have been looking at the EPA test data during that time including the Road Load HP (RLHP) coefficients.  The EPA target RLHP coefficients (based on coast down data) didn't make sense when comparing the C-Max with other cars.  Below is a graph of the RLHP to reach the speeds shown based on EPA coefficients.

 

As you can see, originally the C-Max used the Fusion data to get the 47 mpg - the red curve.  In August 2013, Ford revised the data as shown in the blue curve.  Note that the revised data yields a significant increase in RLHP and thus will result in a drop in FE.  The drop was to 43 mpg or 4 mpg.

 

I also plotted the curve for the Prius V for comparison.  There were six Vs shown in the EPA data - three using the first set of coefficients and three using the second set of coefficients.  I don't know why the need for the two sets of data.  But the curves are very close as seen on the graph.  Note that the C-Max Rev. curve and the two Prius V curves are very close to being the same and hence the FE of the Prius V and C-Max revised ratings were very close to each other - 44/40/42 vs 45/40/43.

 

Now, Ford discovers an error in the coefficients that lowers the C-Max EPA rating to 42/37/40.  So, when we see the new coefficients, one can expect a new curve likely as high above the revised C-Max rating as the revised rating was above the old 47/47/47.  

 

IMO, these EPA coefficients and the resulting FE numbers when compared among vehicles should have triggered Ford engineers working to dig into this difference. I have said this for over a year, how can a heavier, less aerodynamic car, with more frontal area achieve 47 mpg or even 43 mpg in the EPA tests and other hybrids that are lighter, more aerodynamic, and with a smaller frontal area can't.  This is physics not magic.

 

 

    

 

[Marc Smith]

 

This is physics not magic.

    

 

 

Now your starting to sound logical, like Scotty yelling at Kirk...Automakers don't do logical...

[ptjones]

As I've posted in another thread I've done coast down tests on the C-Max over the past year and have been looking at the EPA test data during that time including the Road Load HP (RLHP) coefficients.  The EPA target RLHP coefficients (based on coast down data) didn't make sense when comparing the C-Max with other cars.  Below is a graph of the RLHP to reach the speeds shown based on EPA coefficients.

 

As you can see, originally the C-Max used the Fusion data to get the 47 mpg - the red curve.  In August 2013, Ford revised the data as shown in the blue curve.  Note that the revised data yields a significant increase in RLHP and thus will result in a drop in FE.  The drop was to 43 mpg or 4 mpg.

 

I also plotted the curve for the Prius V for comparison.  There were six Vs shown in the EPA data - three using the first set of coefficients and three using the second set of coefficients.  I don't know why the need for the two sets of data.  But the curves are very close as seen on the graph.  Note that the C-Max Rev. curve and the two Prius V curves are very close to being the same and hence the FE of the Prius V and C-Max revised ratings were very close to each other - 44/40/42 vs 45/40/43.

 

Now, Ford discovers an error in the coefficients that lowers the C-Max EPA rating to 42/37/40.  So, when we see the new coefficients, one can expect a new curve likely as high above the revised C-Max rating as the revised rating was above the old 47/47/47.  

 

IMO, these EPA coefficients and the resulting FE numbers when compared among vehicles should have triggered Ford engineers working to dig into this difference. I have said this for over a year, how can a heavier, less aerodynamic car, with more frontal area achieve 47 mpg or even 43 mpg in the EPA tests and other hybrids that are lighter, more aerodynamic, and with a smaller frontal area can't.  This is physics not magic.

 

 

    

I had a couple of questions on whether how much tire pressure effects efficiency and is it possible that FORD's Hybrid system is more efficient than Prius? With the improvements I have made to MADMAX  I'm getting pretty close to MPG's of my Daughter's 2012 Prius. :) 

 

Paul   

[Marc Smith]

folks on priuschat  have also noticed that the prius hatchback with the 17" wheels  gets lower mileage than the the prius hatch with 15" wheels...

reducing unsprung weight?

 

make you wonder if ford put 15" rims/tires  combo on the cmax  and saved a few pounds  could it help?

[plus 3 golfer]

I don't think the efficiency of the drivetrain of the C-Max vs Prius would be very different - both use atkinson cycle engines and a similar drive systems. Both teams of engineers should be optimizing software for their powertrain components and so forth.  But, the coefficients above are based on roll down / coast down data with the engine not running.

 

Remember we are talking about one significant component in the EPA FE tests - the target coefficients that are used in setting up the dynamometer used in the various EPA drive cycles - not what one can achieve with mods, driving style, and so forth.  Reduce rolling road drag / road HP and FE should increase. Tires are likely set to manufacturer's specs for the tests.

 

Marc Smith, I wonder if the two sets of EPA target coefficients aren't for different option package on the Prius V (like wheels and maybe other items that affect FE). 

[hybridbear]

I don't think the efficiency of the drivetrain of the C-Max vs Prius would be very different - both use atkinson cycle engines and a similar drive systems. Both teams of engineers should be optimizing software for their powertrain components and so forth.  But, the coefficients above are based on roll down / coast down data with the engine not running.

 

Remember we are talking about one significant component in the EPA FE tests - the target coefficients that are used in setting up the dynamometer used in the various EPA drive cycles - not what one can achieve with mods, driving style, and so forth.  Reduce rolling road drag / road HP and FE should increase. Tires are likely set to manufacturer's specs for the tests.

 

Marc Smith, I wonder if the two sets of EPA target coefficients aren't for different option package on the Prius V (like wheels and maybe other items that affect FE). 

While not required by the EPA, Toyota has tended to test individual trim levels separately for the EPA tests. They do this with the Camry Hybrid and I think they've done this with some Prius models.

[SnowStorm]

I don't think the efficiency of the drivetrain of the C-Max vs Prius would be very different - both use atkinson cycle engines and a similar drive systems. Both teams of engineers should be optimizing software for their powertrain components and so forth.  But, the coefficients above are based on roll down / coast down data with the engine not running.

Thanks for graph and coefficients.  But don't they look funny?  The A much higher on the V?  Tires must be a lot worse than on C-Max.  The B coefficient negative?  They better patent that quick.  Bearing friction is helping to push the car along!  And the C one much larger on the V?  Implies larger drag coefficient - everyone claims its lower than C-Max.  So I try curve fitting my coast down data and guess what?  It looks just as weird:

 

38psi  A= +33.382,   B= -0.163734, C= +0.0235199

49psi  A= +45.1284, B= -0.77455,   C= +0.0313688

 

Crazy curve fits!  You should just take a French curve and "eyeball" it!  Those (impossible) negative B coefficients tend to push down the center region - gives better mileage at moderate speeds where most of the EPA runs happen - hmm...   As Alice would say, "curiouser and curiouser"!

 

Regarding drive-train comparison, they are hardly the same (as I understand) when it comes to the battery and electric motor.  The C-Max can leverage the hybrid system longer and to higher speeds than the V.  This difference should be a big help with all the starts/stops and speed changes in the EPA tests.  And less drag, though helpful at 80 mph, doesn't help as much in the EPA tests.  The C-Max is better!

[salsaguy]

Thats a good question.

If they really hid that screen thinking folks hated to see such low numbers and they didnt know how to reset it at the beginning and had old bad data from the dealer and test drivers included in their own data....

just give us the screen. it is what it is and many here get better mph

Id like to hear from Ashley or another Ford rep on why we cant customize the screen or add/subtract what we want to, and Im not talking about MyView

 

Then will Ford bring back the Lifetime screen?

[Marc Smith]

Marc Smith, I wonder if the two sets of EPA target coefficients aren't for different option package on the Prius V (like wheels and maybe other items that affect FE). 

not sure.  the Prius V(wagon)  has the 16" and 17" wheels.  while the prius hatchback  has 15" and 17" options

 

onthe V  the tire size is 205 (16)   and 215(17).  so not much  difference there,  but on the wagon  the 15's are 195, and the 17's are 215...much bigger difference.

 

not sure how much difference there is on weight based on the trim levels.  I'm sure the solar roof/sun roof  adds more weight...

 

I wonder how much FE  the cmax would gain back  through the use of lowering springs...

[plus 3 golfer]

Thanks for graph and coefficients.  But don't they look funny?  The A much higher on the V?  Tires must be a lot worse than on C-Max.  The B coefficient negative?  They better patent that quick.  Bearing friction is helping to push the car along!  And the C one much larger on the V?  Implies larger drag coefficient - everyone claims its lower than C-Max.  So I try curve fitting my coast down data and guess what?  It looks just as weird:

 

38psi  A= +33.382,   B= -0.163734, C= +0.0235199

49psi  A= +45.1284, B= -0.77455,   C= +0.0313688

 

Crazy curve fits!  You should just take a French curve and "eyeball" it!  Those (impossible) negative B coefficients tend to push down the center region - gives better mileage at moderate speeds where most of the EPA runs happen - hmm...   As Alice would say, "curiouser and curiouser"!

 

Regarding drive-train comparison, they are hardly the same (as I understand) when it comes to the battery and electric motor.  The C-Max can leverage the hybrid system longer and to higher speeds than the V.  This difference should be a big help with all the starts/stops and speed changes in the EPA tests.  And less drag, though helpful at 80 mph, doesn't help as much in the EPA tests.  The C-Max is better!

The hardware is similar just different size.  I agree that the C-Max can run at higher speeds in EV and has a larger battery but I haven't seen any evidence that this makes the C-Max significantly more efficient than the Prius.  At higher speeds ICE is running at higher rpm and likely an efficient point on the BSFC (the High ICE mode). So, I don't see that increasing rpm to store more energy for future use has significant efficiency benefits at higher speeds. Yes, one can likely always find specific instances where efficiency might improve significantly (like hypermiling using hills) where the extra battery capacity and the ability to run more in EV helps.  But that's the exception rather than the norm..  At lower speeds, both should be about the same in efficiency.  

 

The target coefficients must be matched to dynamometer coast down data.  So, the dyno software determines the vehicles losses such that the dyno set coefficients are equal to the target coefficients (from coast down data) minus vehicle loss coefficients.  The set coefficients are also reported in the EPA test data. The set coefficients for the C-Max are:

-2.54  0.2511  0.01829

and for the Prius V are:

14.533 -0.17206 0.023768

13.56 -0.23424 0.024158

 

So, using the target coefficients at 50 mph yields: Prius V = 8.7 and 8.3 HP and the C-Max = 7.4 HP.  This is significantly below the curves using target coefficients and likely incorrect for the C-Max.  We need to see what the data looks like once EPA posts the new coefficients.

Edited June 18, 2014 by Plus 3 Golfer

[nsteblay]

Though RLHP and wind resistance are obvious factors I believe the biggest reason for discrepancies in the EPA estimates is temperature.  Toyota has architected their cars to have the engine run constantly over 40 MPH.  They get good highway mileage by running in Negative Split Mode and having a good balance of engine size, car weight and wind resistance.  The Electric Generator (MG1) is providing mechanical power in this mode that allows the smaller and highly efficient ICE to run at optimal MPG.  Because the engine is constantly running it stays warm and can heat the car in the winter.

 

Ford chose to have larger engines to improve power and acceleration.  As stated because of physics the Negative Split Mode in the C-Max can't possibly be as efficient.  Instead Ford architected in such a way that the car can run in EV at higher MPH.  The original ceiling for EV was 63 MPH.  All EPA tests were run under this at a temperature in the 70's.  This allowed the Powersplit architecture to take optimal advantage of EV mode and hence the high numbers.

 

What happens with the C-Max is in cold weather the engine needs to run more often if not constantly depending on how cold.  The C-Max cannot and will not get nearly as good of mileage if the ratio of EV to ICE is less.  Another factor is driving style.  Those that drive to optimize EV time are getting significantly better mileage.  When Ford pushed the EV ceiling up to 85 MPH I started to get significantly better mileage because much of my driving is above 63 MPH.  Even so, unless I want to turn off the heat in the winter I can't achieve good numbers.  Living in Minnesota where we have cold winters I am averaging yearly overall ~40 MPG.  If I were in a warmer climate I would easily be in the mid 40s.  

Edited June 19, 2014 by nsteblay

[plus 3 golfer]

Though RLHP and wind resistance are obvious factors I believe the biggest reason for discrepancies in the EPA estimates is temperature.  Toyota has architected their cars to have the engine run constantly over 40 MPH.  They get good highway mileage by running in Negative Split Mode and having a good balance of engine size, car weight and wind resistance.  The Electric Generator (MG1) is providing mechanical power in this mode that allows the smaller and highly efficient ICE to run at optimal MPG.  Because the engine is constantly running it stays warm and can heat the car in the winter.

 

Ford chose to have larger engines to improve power and acceleration.  As stated because of physics the Negative Split Mode in the C-Max can't possibly be as efficient.  Instead Ford architected in such a way that the car can run in EV at higher MPH.  The original ceiling for EV was 63 MPH.  All EPA tests were run under this at a temperature in the 70's.  This allowed the Powersplit architecture to take optimal advantage of EV mode and hence the high numbers.

 

What happens with the C-Max is in cold weather the engine needs to run more often if not constantly depending on how cold.  The C-Max cannot and will not get nearly as good of mileage if the ratio of EV to ICE is less.  Another factor is driving style.  Those that drive to optimize EV time are getting significantly better mileage.  When Ford pushed the EV ceiling up to 85 MPH I started to get significantly better mileage because much of my driving is above 63 MPH.  Even so, unless I want to turn off the heat in the winter I can't achieve good numbers.  Living in Minnesota where we have cold winters I am averaging yearly overall ~40 MPG.  If I were in a warmer climate I would easily be in the mid 40s.  

I agree.  

 

But as I said before in the revised testing Ford chose to run the 2 EPA cycles (ambient in the 70s) on the C-Max.  Ford could have chose to run all 5 EPA cycles which includes the UDDS Cold Start Cycle (same as City Cycle except the ambient temperature is at 20F).  But Ford didn't.  Why?  Likely because it would have lowered the EPA numbers even more.  A vehicle like the C-Max is likely to have a wide range of reasonable FE numbers depending on geographic location and how it's driven - just like the VW ad I posted in another thread from the 1960s.  It's 54 years later and some things never change. :)

[ptjones]

Though RLHP and wind resistance are obvious factors I believe the biggest reason for discrepancies in the EPA estimates is temperature.  Toyota has architected their cars to have the engine run constantly over 40 MPH.  They get good highway mileage by running in Negative Split Mode and having a good balance of engine size, car weight and wind resistance.  The Electric Generator (MG1) is providing mechanical power in this mode that allows the smaller and highly efficient ICE to run at optimal MPG.  Because the engine is constantly running it stays warm and can heat the car in the winter.

 

Ford chose to have larger engines to improve power and acceleration.  As stated because of physics the Negative Split Mode in the C-Max can't possibly be as efficient.  Instead Ford architected in such a way that the car can run in EV at higher MPH.  The original ceiling for EV was 63 MPH.  All EPA tests were run under this at a temperature in the 70's.  This allowed the Powersplit architecture to take optimal advantage of EV mode and hence the high numbers.

 

What happens with the C-Max is in cold weather the engine needs to run more often if not constantly depending on how cold.  The C-Max cannot and will not get nearly as good of mileage if the ratio of EV to ICE is less.  Another factor is driving style.  Those that drive to optimize EV time are getting significantly better mileage.  When Ford pushed the EV ceiling up to 85 MPH I started to get significantly better mileage because much of my driving is above 63 MPH.  Even so, unless I want to turn off the heat in the winter I can't achieve good numbers.  Living in Minnesota where we have cold winters I am averaging yearly overall ~40 MPG.  If I were in a warmer climate I would easily be in the mid 40s.  

I don't remember if you are using ICE block heater during the winter. Also Grill Covers and Oil Pan heater use during the winter will improve MPG's about 6mpg. :)

 

Paul

[nsteblay]

I don't remember if you are using ICE block heater during the winter. Also Grill Covers and Oil Pan heater use during the winter will improve MPG's about 6mpg. :)

 

Paul

I do have the block heater and use it.  Helps at first but when it's 20 below ...  :gaah:  :gaah:  :gaah:  :gaah:

 

I should look at the Grill Covers.

 

Nick

[ptjones]

I do have the block heater and use it.  Helps at first but when it's 20 below ...  :gaah:  :gaah:  :gaah:  :gaah:

 

I should look at the Grill Covers.

 

Nick

Look into Wolverine Model 9 oil pan heater and Grill Covers will improve mpg's in the Summer time too.  I just went 100miles on Atlanta FWY's and averaged 52mpg with temps high 90's going up and mid 80's coming back with some AC going up. :)

 

Paul