CMAX Grill Cover Testing, 2-5 MPG Gain

[ptjones]

Here are the the facts from all the testing been doing.

 

1. FORD said in Hotline Assistance Request that The Approx. engine Operating Temp should be 202-212deg.F

 

2. The best MPG temp range is 202-230deg.F

 

3. Starting with cold ICE and outside temp from 37-70deg.F driving hwy loop of 14.1mi you gain average of 4.MPG with Grill Covers on vs off.

 

4. 3-4MPG gain city driving.  The Grill Covers heat up ICE quicker and keep it warmer than without Grill Covers. There is about a 30-40deg.F WT difference with Grill Covers on and off. Even at 70deg.F outside temp I could only get to 200deg.F occasionally and most of the time 180-190deg.F. range.

 

5. The Grill Covers really helps short trips 3-10mi because of short heat up time for ICE. Adding oil pan heater improves MPG's another 2mpg.

 

6. Because shutters open when the CMAX is stopped Grill Covers keep ICE warmer longer than without.

 

As more people get experience with Grill Covers we will add more Post.

Edited January 21, 2014 by ptjones

[zhackwyatt]

So to repeat something I think you have said before.  The covers are much more about the temperature than the aerodynamics of the car?

[C-MaxJaxon]

This looks more like a fish story all the time. We're up to 5 MPG now? Next week it will be 6, and maybe 7 or 8 in a couple weeks. Where will it end? ;)

[ptjones]

So to repeat something I think you have said before.  The covers are much more about the temperature than the aerodynamics of the car?

People are finding 2 mpg is an aerodynamic improvement, 3 mpg is a temperature improvement.

 

This looks more like a fish story all the time. We're up to 5 MPG now? Next week it will be 6, and maybe 7 or 8 in a couple weeks. Where will it end? ;)

If you look at the graph the information was there all the time.

[F8L]

I'm still learning about the CMAX so I'm a little foggy on the particulars but are you also monitoring inverter and electric motor temps?

 

Is the grille block easy to remove on the side of the road in the event you forget to remove it before a long trip?

[CNCGeek]

I'm still learning about the CMAX so I'm a little foggy on the particulars but are you also monitoring inverter and electric motor temps? Is the grille block easy to remove on the side of the road in the event you forget to remove it before a long trip?

This would be my concern as well, the inverter temps and the motor temps with the covers installed. 

 

I think the covers are secured with velcro so that would seem pretty easy to remove - but I wonder about stowing the covers in the back on a long trip if it is packed full-o-stuff.

[F8L]

This would be my concern as well, the inverter temps and the motor temps with the covers installed. 

 

I think the covers are secured with velcro so that would seem pretty easy to remove - but I wonder about stowing the covers in the back on a long trip if it is packed full-o-stuff.

 

That sounds easy enough to remove. I asked because I made a trip from Sacramento to LA and forgot about the grille block on my car. While speeding up the grapevine at 80+mph I noticed my engine temp had climbed up to 211F! In a Prius is normally doesn't go any higher than 198F (191F is normal) and that is with full grille block. 211F is way too high. I immediately pulled over and removed the ugly foam we use as a block. Emergency removal is important. ;)

 

I would find out where the radiator for the inverter is. That will help determine how much grille blocking will impact temps.

 

Does the Torque app have the PIDs for the CMAX yet? That is how I was able to monitor all of my temps while testing. My Scangauge is too old to do this as it has not been updated since 2005.

[plus 3 golfer]

There is a dual cooler located behind the lower grill on the C-Max for the CVT and inverter.

[ptjones]

This would be my concern as well, the inverter temps and the motor temps with the covers installed. 

 

I think the covers are secured with velcro so that would seem pretty easy to remove - but I wonder about stowing the covers in the back on a long trip if it is packed full-o-stuff.

The cover have velcro on them so they will stick on the back of seat and not take any space. They are made of Polycarbonate very durable plastic. They can take some abuse, rocks.

 

There is a dual cooler located behind the lower grill on the C-Max for the CVT and inverter.

Is that separate from the radiator? It looks like it is going to the radiator. 

[plus 3 golfer]

The cover have velcro on them so they will stick on the back of seat and not take any space. They are made of Polycarbonate very durable plastic. They can take some abuse, rocks.

 

Is that separate from the radiator? It looks like it is going to the radiator.

 

To confirm everything I'd have to remove the bottom belly cover and look.

 

Looking at the parts diagrams, there is a separate CVT cooler which looks to be behind the lower front grill. There also are 3 electric coolant pumps, - one for the engine (shown in another diagram), one (8C419B) not sure what for yet (possibly for heater core, electric motor) and one for the inverter (8C419A). The one for the inverter appears to be connected to the CVT cooler. Note on the CVT cooler diagram there appears to be a visible coolant connection above the CVT connection. Again, this needs to be verified by pulling the lower cover off and tracing the coolant lines.

 

 

 

Edited January 19, 2013 by Plus 3 Golfer

[C-MaxJaxon]

Here is someone who is trying the foam block method. The only potential problem I see is the wind pressure at 70+ MPH (worse with a head wind) could push the blocks out the back if they aren't fit very tightly.

 

http://www.cleanmpg.com/forums/showthread.php?p=368345

[PWBarrett]

Hey, Plus 3 Golfer - 

Where'd you find a shop manual for a C-Max?  On the Motorcraft site, the closest I've seen is for a Focus Electric.

 

[plus 3 golfer]

Hey, Plus 3 Golfer - 

Where'd you find a shop manual for a C-Max?  On the Motorcraft site, the closest I've seen is for a Focus Electric.

The manual is a parts on-line manual at ford parts.com not a shop manual.

[ptjones]

The manual is a parts on-line manual at ford parts.com not a shop manual.

I checked my inverter coolant lines after a trip by putting my hand on it and it  was cold. Good Job Plus 3 Golfer.

[Roger Eastman]

I wonder if they have changed the active grille shutters since the start of production on the C-Max Hybrid. My SEL was built on 1- 4- 2013 and the grille shutters can completely close off the entire lower and the middle grille components.

[C-MaxJaxon]

The window sticker shows mine was built in late July. It looked like the middle and lower grilles on my car would be covered by the shutters.

[ptjones]

I wonder if they have changed the active grille shutters since the start of production on the C-Max Hybrid. My SEL was built on 1- 4- 2013 and the grille shutters can completely close off the entire lower and the middle grille components.

 

The window sticker shows mine was built in late July. It looked like the middle and lower grilles on my car would be covered by the shutters.

They are closed but there not air tight. The ICE warms up about twice as fast with Grill Covers on. The idea was good but doesn't work as well as intended. I noticed all fusion's have shutters. I'm going to be testing Fusion Hybrid tomorrow with my Grill Covers.

[donhak]

It they were easier to get at, it would be interesting to see if just adding some door insulating tape along the edges would help the shutters to seal tighter.  I think your Grill Covers would be great for Alaska.  When the engine is running to both charge the battery and warm the engine, instantaneous mileage can be under 20 mpg.  We are due to get below zero this weekend and could definitely use them then.

[ptjones]

It they were easier to get at, it would be interesting to see if just adding some door insulating tape along the edges would help the shutters to seal tighter.  I think your Grill Covers would be great for Alaska.  When the engine is running to both charge the battery and warm the engine, instantaneous mileage can be under 20 mpg.  We are due to get below zero this weekend and could definitely use them then.

I don't know where all the leakage comes from but the covers do the job. They also keep snow out of grills. Set My View to impower on left side and water temp gauge on right. The first line is 140deg.F the middle is 180-216+deg.F. 206deg. is ideal for best MPG's.

[OreeGoing]

I tried something different for closing the grill openings.

The cure all Duct Tape!

Half width fits between the grill members and black is hardly noticeable.

 

I have been driving this way for several days and am amazed that the duct tape strips are staying put!

I have seen my mpg go up, but since it has also warmed some here I cannot say exactly how much.

I left the top slot open but covered the rest including the lower all black grill.

Checking the water temperature it still is below 1/2 on the gauge often, so maybe I can do more, but am being cautious.

 

[ptjones]

I tried something different for closing the grill openings.

The cure all Duct Tape!

Half width fits between the grill members and black is hardly noticeable.

 

I have been driving this way for several days and am amazed that the duct tape strips are staying put!

I have seen my mpg go up, but since it has also warmed some here I cannot say exactly how much.

I left the top slot open but covered the rest including the lower all black grill.

Checking the water temperature it still is below 1/2 on the gauge often, so maybe I can do more, but am being cautious.

 

IMG_7007s.jpgIMG_7008s.jpg

Good Job but you need to close off the hole thing, you're safe to 70deg.F anyway. If the temp gauge doesn't go to the middle it means you are not getting to180deg.F and you need to get to 206deg.F. If you are worried get a ScanGauge and you will see exactly what temp you are at. You wouldn't believe how cold the ICE runs. Then you will want some Grill Covers. :)  

[robodog61]

Hello PT Jones.  I have some weird data with the Ford and grill covers and my Prius with foam blocking.  The Prius comes up to temp much quicker.  I can get to 180 fairly quickly and the max temp I have seen is about 193.  I think that is the normal temp range for the Prius.  It is very stable around that temp with outside air temps from about 10 degrees to the mid 20's.  I have noticed that the Prius engine runs more often and spends less time than the Ford in EV mode.  However, with scan gauge I can tell that the gallons per hour is quite a bit lower under load that the C Max.  With the foam covers and driving in mix of local and highway, I can run the heat and get about 50-51 mpg.  I think that is about 2-5 mpg more than before I installed the foam

With the C-Max, I tend to take it on shorter trips.  Even on a 15 mile trip, the water temp never went above 180 and was usually about 150-170.  It spent a lot of time in EV mode, but when the engine ran, it took about 2-2.5 GPH vs. 1-1.5 with the Prius.  I really couldn't run the heat since the WT was so low. With this extreme cold and the grill covers on, I have been getting about 40 mpg and that is driving in order to maximize my mpg.

 

These are just some observations about the differences between the 2 cars.  I don't know how I can get the WT higher in the Ford on local trips, even long ones.

[ptjones]

 

 

Hello PT Jones.  I have some weird data with the Ford and grill covers and my Prius with foam blocking.  The Prius comes up to temp much quicker.  I can get to 180 fairly quickly and the max temp I have seen is about 193.  I think that is the normal temp range for the Prius.  It is very stable around that temp with outside air temps from about 10 degrees to the mid 20's.  I have noticed that the Prius engine runs more often and spends less time than the Ford in EV mode.  However, with scan gauge I can tell that the gallons per hour is quite a bit lower under load that the C Max.  With the foam covers and driving in mix of local and highway, I can run the heat and get about 50-51 mpg.  I think that is about 2-5 mpg more than before I installed the foam

With the C-Max, I tend to take it on shorter trips.  Even on a 15 mile trip, the water temp never went above 180 and was usually about 150-170.  It spent a lot of time in EV mode, but when the engine ran, it took about 2-2.5 GPH vs. 1-1.5 with the Prius.  I really couldn't run the heat since the WT was so low. With this extreme cold and the grill covers on, I have been getting about 40 mpg and that is driving in order to maximize my mpg.

 

These are just some observations about the differences between the 2 cars.  I don't know how I can get the WT higher in the Ford on local trips, even long ones.

The reason the GPH is high is you have a Lithium ion battery with about twice the capacity of the Prius and it can be charged faster too. This takes alot of power from ICE for a short time. I have been able to get 70%EV Mod around town which leaves 30% of the time for fast charging.  I believe FORD has over cooled the ICE and if you didn't need to use the AC you could leave the covers on all year long for city driving. If you have all the grill openings blocked off I don't know what else you can do. The thermostat is fully open at 202deg.F.  Maybe Oil pan heater or engine block heater would help.

Edited January 27, 2013 by ptjones

[hybridbear]

I tried something different for closing the grill openings.

The cure all Duct Tape!

Half width fits between the grill members and black is hardly noticeable.

 

I have been driving this way for several days and am amazed that the duct tape strips are staying put!

I have seen my mpg go up, but since it has also warmed some here I cannot say exactly how much.

I left the top slot open but covered the rest including the lower all black grill.

Checking the water temperature it still is below 1/2 on the gauge often, so maybe I can do more, but am being cautious.

 

IMG_7007s.jpgIMG_7008s.jpg

How has the tape held up?

[jchaddpete]

Can someone suggest where Grill Covers can be purchased?  Apparently, my Ford dealership isn't aware that they make a difference in mpg during colder temps so I suspect they're not available as a Ford product.

Any advice would be appreciated.