fbov Posted January 16, 2014 Report Share Posted January 16, 2014 (edited) First off, Mike, you are the man; thanks for the spoiler detail as that had to be dity work! I had Hucho's Aerodynamics of Road Vehicle on my Christmas list, and Santa was good to me...The two lessons I've gleaned after paging through the whole thing, and reading the first few chapters: Aerodymanic optimization involves a lot more than drag reduction, as drag has benefits that are critical to car design. Minimum drag cars are undrivable, and DIY drag reduciton can be dangerous. Equivalent drag coefficient for cars can be achieved by starting with the right shape (like the C-Max) or by optimizing the details of a less intuitive, albeit more aesthetic shape. From this perspective, Ford is doing detail optimization in 2014.- The rear window bumps look like an attempt to reduce energy transferred to the trailing vortices coming off the roof.- the front and rear wheel spoilers are a common way of reducing wheel drag- we haven't seen the hood mods, but there's a lot of room for improvement, so let's assume they did. You'll recall that tuft testing showed a very sharp break at the window edge - air flow on the glass was nearly perpendicular to the high-speed flow coming off the C-pillar. Rear window mods should serve to move that break farther back, reducing the area of the back window that's experiencing low pressure. It may also reduce the energy lost to the trailing vortices coming off the roofline. Both reduce drag without upsetting stability (lift and center of pressure substantiall unchanged) The tire spoilers were already there, and I have to wonder why they didn't integrate the additions; they really look tacked-on. But, moving tires are one of the big sources of drag, and if you part the air in from of them, they have less. Again, you'd need a wind tunnel to be sure it's an improvement, but detail optimization proceeds by trial and error. At the same time, I'm intrigued to learn what they didn't do.- front air dam- reduced cooling airflow- side skirts, not just a bump before the tire- rear diffuser- any sort of vortex generator, anywhere. I can understand the last on aesthetic grounds, but members here have seem real improvements from the first couple things... It has to do with lift and stability at speed, if I read things right. A deeper air dam reduces drag, but it also reduces front lift. I suspect the grill blocks are doing the same thing, lowering both drag and lift. Sounds like real improvement, until you research aerodynamics and learn that you've also made the car unstable at speed. Stability has to do with the "centers" where the forces act. For gravity, it's the "center of mass" (CM) where all forces can be assumed to act on the body. For aerodynamics, it's "center of pressure" (CP), where all the aerodymanic forces pressing on the car's skin can be assumed to act. Anything you do to reduce front drag moves the CP forward, and since drag increases with speed, driving faster increases the magnitude of that force. CP behind CM is stable as the aero forces tend to align the car into the wind. CP in front of CM is unstable, as aero forces try force the car across the wind. A combination of high load (moves CM back), front aero mods, and high speed can result in a car that wants to crash. Ford has to avoid that. It's a good thing for us to do, too. HAve fun,Frank Edited January 16, 2014 by fbov ptjones, C-MaxSea and bemyax 3 Quote Link to comment Share on other sites More sharing options...
mtb9153 Posted January 16, 2014 Report Share Posted January 16, 2014 Frank, impressive facts thanks for taking the time to share them here. As for the air dam and a rear diffuser, these are the two things I plan to address next. The air dam will be first and easiest to construct. Stay tuned, Brother Mike Quote Link to comment Share on other sites More sharing options...
anilruia Posted January 16, 2014 Report Share Posted January 16, 2014 I have been in the market for a C-Max hybrid for a while and waiting for the 2014 hybrids to come in to hopefully fix the first generation bugs.I see that all the dealers in my area now show 2014 C-Max hybrid in their inventory - as dealer ordered - so not yet physically in the inventory, but should mean that the factory production must have started or be close to starting. Jaydrama 1 Quote Link to comment Share on other sites More sharing options...
fbov Posted January 16, 2014 Report Share Posted January 16, 2014 ... As for the air dam and a rear diffuser, these are the two things I plan to address next. ...I suspect that you may balance one with the other... and I'm on the airdam/grill block bandwagon, just working slowly to understand the elements of a change.Frank Quote Link to comment Share on other sites More sharing options...
salsaguy Posted January 17, 2014 Report Share Posted January 17, 2014 If the cmax computer hasn't been tweaked to adjust for any add ons you put or oil change then they will be moot since its not set up that way in the first place. It's not just hardware folks, it's a system that has to work together. If they could do it cheaply for the 2013s to help avoid negative feedback / tattoos, don't you think they would? Brother Jus I for one will push for the incorporation of the 2014 changes to our 2013 models. It is only right that we should be able to benefit from them and not be excluded just because we bought the first generation CMax. If nothing else I think Ford should offer them to us because we pioneered and brought to light the weaknesses they produced into the 2013. Test mule's so to speak. Quote Link to comment Share on other sites More sharing options...
salsaguy Posted January 17, 2014 Report Share Posted January 17, 2014 Still no hybrid cmaxes in inventory near me.only energies. I saw a brand new candy blue (looked aquamarine to me) energi on the way to work yesterday right in front of me. No plates yet. The new blue looks different (more toyish) than last year's blue at least on my eyes.was a bright sunny day so not sure if that was part of it Quote Link to comment Share on other sites More sharing options...
HendersonD Posted January 17, 2014 Report Share Posted January 17, 2014 Can someone check something for me. I am on my iphone looking at fords website and it appears that mpg for the 2014 cmax was finally posted. Just a few days ago it was listed as TBD. If what I am seeing is correct the mileage did not change from the 2013 model, still 40/43/45. A browser on a smartphone is a bit tough to use so I may be wrong Quote Link to comment Share on other sites More sharing options...
ceemax71 Posted January 17, 2014 Report Share Posted January 17, 2014 Can someone check something for me. I am on my iphone looking at fords website and it appears that mpg for the 2014 cmax was finally posted. Just a few days ago it was listed as TBD. If what I am seeing is correct the mileage did not change from the 2013 model, still 40/43/45. A browser on a smartphone is a bit tough to use so I may be wrong40/43/45 is what is shown on the new window stickers. Quote Link to comment Share on other sites More sharing options...
HendersonD Posted January 17, 2014 Report Share Posted January 17, 2014 Wow, ford made a big deal a few months back about the changes to the 2014 model to increase mpgWhat happened? Quote Link to comment Share on other sites More sharing options...
ptjones Posted January 17, 2014 Report Share Posted January 17, 2014 (edited) I just looked at Ford's site and it didn't say anything about mileage. :) I would be surprised if there was a difference, they aren't going to take any chances now. Paul Edited January 17, 2014 by ptjones ScubaDadMiami and C-MaxSea 2 Quote Link to comment Share on other sites More sharing options...
HendersonD Posted January 17, 2014 Report Share Posted January 17, 2014 Did you look under engine specs? Quote Link to comment Share on other sites More sharing options...
ptjones Posted January 17, 2014 Report Share Posted January 17, 2014 Engine specs still say TBD. Paul Quote Link to comment Share on other sites More sharing options...
bigalpha Posted January 17, 2014 Report Share Posted January 17, 2014 Does anyone know if they fixed the crummy visors, or added in-cabin storage anywhere? Quote Link to comment Share on other sites More sharing options...
HannahWCU Posted January 18, 2014 Report Share Posted January 18, 2014 My guess is the improvements don't show up in the EPA tests, but most likely end up helping real world MPG. Especially since real world mileage is what was the problem from the start. Increasing EPA MPG will just cause all the news media to test it again to see if it gets those "better" MPG. salsaguy 1 Quote Link to comment Share on other sites More sharing options...
maxed-out Posted January 18, 2014 Report Share Posted January 18, 2014 (edited) I think it's far more likely that the reason the numbers are the exact same for the 2014 straight Hybrid C-Max, is because since they are finally on the verge of actually producing them.. and since they have to show something for MPG figures on stickers to sell them.. they are simply borrowing the final figures from the last model year C-Max as allowed to by the EPA. The figures are "conservative" at this point, and will likely change once the EPA tests are complete. Edited January 18, 2014 by maxed-out Quote Link to comment Share on other sites More sharing options...
C-MaxSea Posted January 18, 2014 Report Share Posted January 18, 2014 'No news is good news' with regard to MPG's. Our C-Max took a whipping (not Ford) in the last few months, undeservedly so. Greetings anilruia in Seattle. Nick Quote Link to comment Share on other sites More sharing options...
ArizonaEnergi Posted January 18, 2014 Report Share Posted January 18, 2014 Perhaps the EPA test won't detect the hood-sealing, air dams, and rear fins that the 2014's have so the official MPG rating will be the same? Quote Link to comment Share on other sites More sharing options...
HPRifleman Posted January 18, 2014 Report Share Posted January 18, 2014 Isn't the EPA mileage test done indoors on a stationary machine? If so, doesn't that negate any aerodynamic effects? Quote Link to comment Share on other sites More sharing options...
plus 3 golfer Posted January 18, 2014 Report Share Posted January 18, 2014 Isn't the EPA mileage test done indoors on a stationary machine? If so, doesn't that negate any aerodynamic effects?This has been asked and answered before. Quote Link to comment Share on other sites More sharing options...
ScubaDadMiami Posted January 18, 2014 Report Share Posted January 18, 2014 I just looked at Ford's site and it didn't say anything about mileage. :) I would be surprised if there was a difference, they aren't going to take any chances now. PaulAgreed. Better to underpromise and overdeliver. salsaguy 1 Quote Link to comment Share on other sites More sharing options...
HannahWCU Posted January 20, 2014 Report Share Posted January 20, 2014 2014 Window stickers show same EPA estimates as 2013 (45/40/43). At least for the VINs that have been posted in other threads. Quote Link to comment Share on other sites More sharing options...
salsaguy Posted January 20, 2014 Report Share Posted January 20, 2014 I agree they should have under posted for 2013 and over achieved... that would have given them a huge edge over the Prius.but since everyone is a numbers person they felt they had to beat them on paper not in real world. It hurt them in bad press and word of mouth. Let's hope 2014 is better for the cmax but I fear the hype of the new tech has worn off and the bad press will take some air out of their campaign.Right now the new c-max commercials are taking about how it's more powerful than the Prius not how it's more fuel efficient. Quote Link to comment Share on other sites More sharing options...
HPRifleman Posted January 20, 2014 Report Share Posted January 20, 2014 This has been asked and answered before.Thank you for the reference. These forums have a lot of information that can sometimes get buried. Quote Link to comment Share on other sites More sharing options...
HannahWCU Posted January 20, 2014 Report Share Posted January 20, 2014 it's posted now (45 city/ 40 hwy/ 43 combined MPG): http://www.ford.com/cars/cmax/specifications/engine/ I just looked at Ford's site and it didn't say anything about mileage. :) I would be surprised if there was a difference, they aren't going to take any chances now. Paul ptjones 1 Quote Link to comment Share on other sites More sharing options...
ptjones Posted January 20, 2014 Report Share Posted January 20, 2014 it's posted now (45 city/ 40 hwy/ 43 combined MPG): http://www.ford.com/cars/cmax/specifications/engine/I kept the tab open and sure enough when I refreshed it, it came up. Thanks Paul Quote Link to comment Share on other sites More sharing options...
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