I have a Prius and my wife recently got a Fusion Hybrid. I block off my grille every winter to keep it warmer longer and thus increase the mpg a bit. Will this also work with the Fusion hybrid, or does it not work the same as the Prius? Thanks in advance for your input.

 

I don't own a Fusion, but I do own a Hybrid Escape, which is a close relative.
I can say it for sure helps the Escape.
So I'm 99% sure it will help your Fusion as well, namely, the engine will shut off sooner, and drive off battery only for longer intervals in winter time. Good luck, and post back how this simple mod works for you.

-John

 

Shouldn't the cooling system in the force the car to warm up sooner by restricting water flow so that it heats up optimally in cold ambient temps? It seems like it could maybe do some long term harm in running components hotter than the entire system was otpimized to run at by restricting airflow, if that is what you are doing. Don't know of course but it makes me wonder.

 

The short answer is no.

If the car is in motion, there is a tremendous amount of forced air into, and under the hood. This forced air has tremendous cooling effect.

Unless the car is under extreeme load (full throttle for extended length) it is undesireable to have this forced air.

In the Ford Escape, I can't make the car hotter. ( By can't, I mean it is very difficult, since this car uses so little fuel )
I just make it get to normal sooner, and keep it normal temperature longer under EV ( battery only ) driving conditions.

HTH,
-John

 

It seems to me restricting airflow over the thru the radiator and over the ICE will primarily allow the ICE to get up to temperature quicker, which should only affect the point at which the car goes in to or stays in EV when the car heater is turned on. For example, if I use the car's heated seats, and don't turn on the car's climate control system to maintain a warmer temp than ambient on a cold day, then EV mode will happen regardless of whether or not the ICE comes up to temp quicker. The real issue to me in cold weather is that the ambient temp of the battery is too cool, and that this lowers the power output from the [cold] battery. Does this maneuver have any affect on hybrid battery temp?

 

That's it. I don't have the particulars for the Fusion, just the 2005-2007 Hybrid Escape.

In the Escape you need to hit 156'F engine temperature to enter EV mode the first time. After that, for the rest of the drive, the car needs to be above 140'F to allow future EV driving. Once in EV, you can keep driving until the engine cools to 125'F then the engine is forced on no matter what.

The car's thermostat to allow water to flow into the radiator is IIRC 180'F ( might be 190'F so check if you can. )

Ultimately, I'm trying my best to keep the car above 140'F, which is surprizingly hard to do in below freezing weather, so blocking the front grille only helps.
In fact, I don't get warmer than 190'F water if the outside weather is 55 degrees or cooler. At 60'F OAT, my FEH might hit 195'F... if I push it hard! This is with the grille blocked.

 

That is not the case with my FFH. As long as I don't put demands on this routine by turning up the heat it does not come in to play and car goes into EV mode very quickly. As I say, the heated seats and a good jacket help! My wife also has a FEH, and hers is different: does not go into EV until warmed up if I recall. It's a 2007.

 

One aspect of the Sanyo batteries used by Ford is they are "self heating".
This is generally a negative aspect ( hence the A/C cooling ) but is an asset in winter. They have 1-2 Ohms per cell x 250 cells. Punch it hard to draw a lot of amps a few time, and you can raise the battery temperature 4 degrees in 5 seconds of aceleration. Do this 5 or 6 times and your battery is "warm".

You're right, about battery output is nearly linear with temperture.


And blocking the radiator has no effect on heating the battery.

 

I am away from home without my grille block and am paying the price.
Got stuck in sub-zero weather in the center of the country this week.

I drove around town at zero degrees for 30 minutes.
I needed heat to the cabin ( obviously ).
My engine water temperature NEVER EVER PASSED 145 degrees.
It fact, when stopped, engine on, I watched my temp drop a few degrees.
When really cold, the FEH runs FAST IDLE.
My car never got hot enough in 30 minutues to drop out of fast idle.
At stoplights, with my foot on the brake, It was at 1700 RPM.
When it's +20'F the fast idle is 1300 RPM.
Once, at -20'F the fast idle was 2000 RPM.

I emailed the Ford engineering dept back in 2006 and was told this behavior was not deliberatly designed into the programming, but other factors such as all the sensors were contributing to cause this effect. They said they were a little surprised by this, but not concerned.

-John

 

Grille block will help in multiple ways; the airflow will bypass the car's radiator - thus reducing drag and the radiator will retain heat needed for cabin - thus allowing the ICE to not run as often. On the FFH, battery cooling/heat is drawn from the cabin air via a duct beneath the rear seat.