C-max reliability data

[djc]

I was not familiar with the site carcomplaints.com.    It provides car reliability data, and was recommended in an article on Camry vs. Accord reliability at torquenews.  Might be useful for used car buyers:

 

https://www.carcomplaints.com/Ford/C-Max_Hybrid/

 

The 2013 C-max hybrid is reported as having many more problems than subsequent years, with main early problem being the dead 12-volt battery.

Of course that doesn't mean the 2013 is any less reliable now - early problems often get fixed and are a problem only for first owner.

[ptjones]

Only the small percentage owners that had problems complained while most of us never had any problems with our 2013 CMAX other than trans and FORD fixed at no cost and with 247k miles things are still working good.?

 

Paul

Edited March 13, 2020 by ptjones

[fbov]

Paul, we have/had SELs. The SEs had lots of 12v issues that should show up in this kind of thing...

Frank

[jestevens]

Haven't put a dime into my SEL except for tires, light bulbs, cabin filter, oil changes and a new 12V battery after its useful service life.  Have 104K mi now, I will go in for 100K mi service once oil minder comes on.  For that service I do expect to spend some $$ but hard to complain.

Edited March 13, 2020 by jestevens

[ptjones]

8 hours ago, fbov said:

Paul, we have/had SELs. The SEs had lots of 12v issues that should show up in this kind of thing...

Frank

This is also true.

 

Paul

[homestead]

My 2013 SEL Hybrid has had these problems since new.

Wiring under driver seat connector affected seat heater.

Passenger seat heater not working.

Carpet pulled up in back of car, they re-glued it.

half-dozen recalls were done

3 sync updates

auto unlock on driver door is currently only working 50% of time

57k miles on car still getting 45mpg lifetime

Changed to solid lug nuts even though the original ones were still ok.

Just replaced tires with OEM ES at Costco for $742,

Costco put in only 35psi of nitrogen because they said that is what Ford specs for C-max even though the door sticker says 38.

I had them up it to 40psi.

[Lacienega]

Hoemstead, your sticker says 38 PSI? My 2014 cmax says 40 PSI, and most of the time I brought it to the dealer, they lower it to 35.

[C-MaxA2]

I have been running our 2016 C-Max (with the Energy Saving Michelins) at 50 psi.  The max is 51 (for a reason).  I called and talked to Michelin and they said it was fine if I was OK with the 'ride'.  I recently bought a used 2017 (now we have 2 of them) and the selling dealer had to tires at 36-37 psi. My wife and I drove both cars home (50+ miles) at the same speed on the same road.  I got 35 mpg.  She got 45 mpg.  When I got home I pumped the new C-Max to 50 psi and now I'm in the mid 40s mpg. 

 

The tire sticker does not know what tires you have on your car.  How can it?  Just check the sidewall of the tires on your car and trust what the manufacturer of the tires says. 

 

The ride at 50 psi is very close to what it feels like at 35 psi in my opinion (see experiment above).  My wife doesn't like a rough ride but she's fine with the way things feel on our 50 psi C-Max. 

 

Paul - can you chime in there?

[homestead]

36 minutes ago, Lacienega said:

Hoemstead, your sticker says 38 PSI? My 2014 cmax says 40 PSI, and most of the time I brought it to the dealer, they lower it to 35.

 

Yes,  here it is below.  They must have changed it

[JAZ]

I'm neither Paul nor do I play him on TV, but a 28% increase in fuel economy with a nominal 35% increase in tire pressure seems way our of line.  Perhaps your wife is more of a pulse and glider?

[ptjones]

1 hour ago, C-MaxA2 said:

I have been running our 2016 C-Max (with the Energy Saving Michelins) at 50 psi.  The max is 51 (for a reason).  I called and talked to Michelin and they said it was fine if I was OK with the 'ride'.  I recently bought a used 2017 (now we have 2 of them) and the selling dealer had to tires at 36-37 psi. My wife and I drove both cars home (50+ miles) at the same speed on the same road.  I got 35 mpg.  She got 45 mpg.  When I got home I pumped the new C-Max to 50 psi and now I'm in the mid 40s mpg. 

 

The tire sticker does not know what tires you have on your car.  How can it?  Just check the sidewall of the tires on your car and trust what the manufacturer of the tires says. 

 

The ride at 50 psi is very close to what it feels like at 35 psi in my opinion (see experiment above).  My wife doesn't like a rough ride but she's fine with the way things feel on our 50 psi C-Max. 

 

Paul - can you chime in there?

How far did you drive? That seems like a big improvement.

You know I like the better MPG's of 50 psi, I think at most the improvement is 1.5 mpg, I get most of my improvement from Grill Covers(4mpg), wheel covers(2 mpg) and Premium Gas (1-2 mpg). I didn't know the tire pressure was different on the 2014. wonder if newer ones are also 40 psi.

 

Paul

Edited March 13, 2020 by ptjones

[plus 3 golfer]

18 hours ago, C-MaxA2 said:

I have been running our 2016 C-Max (with the Energy Saving Michelins) at 50 psi.  The max is 51 (for a reason).  I called and talked to Michelin and they said it was fine if I was OK with the 'ride'.  I recently bought a used 2017 (now we have 2 of them) and the selling dealer had to tires at 36-37 psi. My wife and I drove both cars home (50+ miles) at the same speed on the same road.  I got 35 mpg.  She got 45 mpg.  When I got home I pumped the new C-Max to 50 psi and now I'm in the mid 40s mpg. 

 

The tire sticker does not know what tires you have on your car.  How can it?  Just check the sidewall of the tires on your car and trust what the manufacturer of the tires says. 

 

The ride at 50 psi is very close to what it feels like at 35 psi in my opinion (see experiment above).  My wife doesn't like a rough ride but she's fine with the way things feel on our 50 psi C-Max. 

 

Paul - can you chime in there?

It's virtually impossible for a 37% (50-36.5)/36.5 increase in tire pressure to account for a 29% (45-35)/35 FE increase in fuel economy unless perhaps you were creeping along at less than 10 mph.?  But there is no question that increasing the psi from around 36-37 to around 50 psi will improve fuel economy.

 

For example, the change in rolling resistance (RR) due to a tire pressure change would be a small part of the drag of a car at normal driving speeds.  Below is a chart of the road load HP of the 2013 C-Max (I don't feel like looking up the 2016 / 2017 data but it will be very similar if it was changed at all) at various speeds based on the data which Ford submitted to the EPA.  The decrease in RR by increasing tire pressure is less than the percent change in pressure.  Again, I don't feel like looking up the numbers from studies and tests but for the range we are talking about, I would say that a 37% increase in psi might be as high as a 25% decrease in RR.  So, applying the 25% reduction in RR to the blue bars the chart below, one can see that if ones speed were 30 mph, one would expect RLHP to decrease by 12.5% (50% * 25%).  Assuming this decrease in RLHP results in a 1:1 increase in fuel economy.  Once might expect the 35 mpg to go up by 12.5% or up to 39 mpg if driving at 30 mph.  Now at 50 mph speed, the 35 mpg would only go up about 7.4 % to 37.6 mpg.   (See my post below for lowering the 25% reduction in RR to more appropriate levels).

 

Also, one must note that the RLHP coefficients used by the EPA are based on coast down data and rolling resistance may affect a small portion of the red bars.  The green bars represent aerodynamic drag. In addition, if you have mods that decrease aerodynamic drag by say 10%, the green bars would be lower by 10 % and the effect of increasing tire pressure on fuel economy would be greater as the blue bar % would increase.

 

Edited March 14, 2020 by Plus 3 Golfer

[fbov]

PM sent to Plus 3.

[plus 3 golfer]

Ok, I looked up the generally accepted equation for rolling coefficient of car tires versus tire pressure which is shown below.  So, one can estimate the %  change in the coefficient for changes in inflation pressure.  The 25 % estimate I used in my previous post is too high and should be between about 15% to 20% for speed between about 30 mph to about 70 mph for the increase in pressure from about 36-37 psi to 50 psi.  So, at 30 mph, one might see their mpg go up 7.5 % and at say 70mph might see their mpg go up 3.6% by increasing their tire pressure from 36.5 psi to 50 psi.

 

Rolling Coefficients Cars

The rolling coefficients for air filled tires on dry roads can be estimated

c = 0.005 + (1 / p) (0.01 + 0.0095 (v / 100)²)                     (3)

where 

c = rolling coefficient

p = tire pressure (bar)

v = velocity (km/h)