Everyone,

I have noticed that the hybrid seems to use higher RPM's to allow the temperature to be better maintained.

For example, @ 55 mph, running down the highway(when the motor is cold and its 0 out), I have observed my RPM's runing at a constant 2500. Then after about 5-7 minutes of this, I can see the RPM's drop down to the 1500 or so that it should be on flat roadways at 55.

The hybrid must not allow the transmission to fully adjust, or maybe its a funciton of the transmission just being cold and it takes it awhile to warm up.

I do park my vehicle in a 55-60 degree heated garage, so I wouldn't think the cold transmission would be the case.....

Any thoughts on this? Would a water heater benefit beyound my heated garage? The hoods for the front end I have seen on this site wouln't seem to function well for a MMH as much as an Escape.

 

Check out my post 17 & still loving it That this seems to be Norm, we don't have an explanitaion as to why, but it appears accros all years and seems directly tied to temps. At min freezing, but 20 or lowere definatly triggers this behavior. Could be EPA emmisions trying to maintain a certain level. as one poster points out.
I suppose if low temps are norm for a long period, a radiator block would help. I don't plan on doing it as here the weather changes daily. Yes it was 20 for 2-3 days, but it's going to be 60+ for the next few as well, I'm to lazy to remove the block as it warms back up.

But the short answer is for unknown reasons, this is norm.

 

The US patent Ford was granted in this regard indicates that the level of regenerative braking to be used, are "tried" for, is significantly reduced if the OAT is below or hovers around freezing. Knowing this, I would imagine the engineers have designed the firmware to keep the battery at a higher level of charge using the ICE, primarily, in those conditions.

That along with the need to provide HOT coolant for heating the cabin might explain consistently higher engine RPM operation in COLD weather.

As many FWD and F/AWD drivers learn, some the HARD way, engine compression braking, or in this case regenerative braking, on only the front wheels can quickly turn hazardous on a slippery roadbed or more especially a sudden unexpected encounter wiith black ice.

I suspect that may be the reason, or at least one of the reasons, we are seeing fewer and fewer FWD and F/AWD vehicles with manual transmissions.

 

[quote=wwest;159810]The US patent Ford was granted in this regard indicates that the level of regenerative braking to be used, are "tried" for, is significantly reduced if the OAT is below or hovers around freezing.

Yes and No. That is until the hybrid battery warms up, there is a reduction in regenerative braking.


Knowing this, I would imagine the engineers have designed the firmware to keep the battery at a higher level of charge using the ICE, primarily, in those conditions.

I have not noticed this at all--that is the hybrid battery remains at a higher level of charge in those conditions. See below.

That along with the need to provide HOT coolant for heating the cabin might explain consistently higher engine RPM operation in COLD weather.

The hybrid battery needs to heat up for the vehicle to become efficient. Cabin heat certainly helps. However John (GPSman1) recent theory is the hybrid battery's SOC goes up and down during cold weather as a heat generating mechanicism until the hybrid battery is 60F.

or in this case regenerative braking, on only the front wheels quote]

Regenerative braking only on the front wheels? Where did this come from?

 

Regenerative braking always comes from front tires only, as the front is where the transmission is on all models. Isn't it true that the rear wheels are rarely powered in AWD models? All 4 tires have disc brakes of course.

 

Another learning exerpience here. I was "thinking" unbalance when in AWD.

 

No, given the wording of the patent it appears the reduction in regenerative braking in cold weather is more to reduce instances of loss of directional control due to inadvertent "braking" of the front stearing wheels.

The second aspect of the patent involves disabling ALL regenerative braking the instant ABS activates during actual braking. Otherwise regenerative braking might overcome ABS' ability to release hydraulic braking and thereby allow the driver to maintain directional control.

Plus, if it were to allow for time to warm up the battery why a setpoint of freezing and not something like 45F??

 

[quote=Billyk;159849]Ignore.

 

I hope that this is not too far off topic, and I apologize if the info has been noted before.

Here's a pdf of some 2006 research including some cold weather data using a 05FEH.

http://www.c2p2online.com/documents/...hristenson.pdf

Hugo

 

Hugo- Thanks for posting. That report had some good points, and some not so good points. Is shows that what Ford says is true. The FEH is the cleanest burning gasoline car money can buy.

However, since it was put on a dyno, it looks like EV mode was NOT taken advantage of... Thus the city ( New York City Cycle ) showed almost double the fuel use, and that is positively FALSE.

With a human driver behind the wheel, city driving ALWAYS yields be better MPG and I don't car about the weather.

Cold reduces my MPG no matter what... but at 0'F, I still get higher numbers in winter during city drives.

I would like to clarify / confirm what Bill was saying.
When both the engine and battery pack are warmed up fully, I get FULL or nearly FULL REGEN BRAKES even at zero degrees F (-18C) OAT.

( I can confirm ~50 amps of regen at zero degrees.) -John