Winter driving too cold weather MPG down

It isn't supposed to work in EV mode at 0 degrees. At about 14 degrees, or below, the car automatically disregards EV and favors gas, for a variety of reasons. There are some exceptions, such as leaving the car plugged in with battery pre-heating. But that fails too once you're out there driving for a while.

We must have at least 10 threads on this now in the main Prime forum. Please read those. Hundreds of posts with answers. This is also covered in your owner's manual.

 

in regards of post #1 , No matter what happen the car control everything

-25C this morning , battery full 100% , and the car has started the engine immediately ( no front defrost activated ). On my 20 Km trip , the EV mode light was on but the car worked in hybrid mode ( engine + electric ) , cabin temp was set at Eco 18 C + heated seat +steering wheel. I observed the energy monitor and Half way on my trip the engine started to cut-off on downhills , maybe 4Km of the trip was pure EV ( no red lines at all ) i arrived at my destination with 85% battery left. NOTE : the car was plugged all night and the battery was already full but the battery heater worked 100% of the time because my Level 2 charger light was '' green '' meaning that the car was pumping some ''juice''.

 

Happy New Year! Boston has now had its longest stretch of sub-20-degree days since they started keeping records back in 1872.

I've decided that letting the engine run to heat the cabin is a better alternative to hypothermia and frostbite.

But I notice from the Prime's charging system display that the when the engine comes on in EV mode, the graphic shows energy flowing from the engine to the traction battery and the traction battery then both powering the climate-control heat pump and providing propulsion to the front wheels. When coasting downhill, the display is a virtual riot of red, yellow and green energy flowing every which-way.

Throughout all this, the EV symbol remains lighted -- not the HV symbol.

I know there Prime has a fancy mechanical transmission that allows the gas engine to work with the electric traction motor in HV mode, but I am wondering if when the engine runs in EV mode, the Prime's gas engine functions more like the diesel engine of a diesel-electric locomotive. In the locomotive, the diesel engine powers a generator which in turn provides electricity to the traction motors. In the Prime, does the gas engine in EV mode similarly serve to charge the traction battery?

Possibly someone more knowledgeable can provide better insight into how various systems interact when the Prime's engine is running just to provide cabin heat.

 

Been -17 and -15 the last two mornings here. I did not drive far but got 44 mpg and 36 mpg on both trips. That means the ICE is going to come on no matter what. I actually wanted it on to warm up the engine. Sucks but this extreme weather will not last forever.

 

The winters in the Midwest are one reason I would not buy an all electric vehicle. In this weather I want backup from the cold.

 

I am not the expert, but a couple of things I understand are happening to keep the ICE running. First the regen battery needs heat to run most efficiently, and #2, the catalytic converter must be at a certain temp to be most effective. Remember, the Prius philosophy is low emissions first, then high mpg's.

Posted via the PriusChat mobile app.

 

Put one on right away on our '08, as it was my wife's work car. (mail carrier 6 days a week). Our '16 does not have one, as we are now both retired. When the weather is this crappy, we just stay home

 

Err ... why ?

One general idea behind efficient cold weather driving is to heat up the ICE once ... and only once. And to keep the ICE warm throughout the drive. I've been doing better now that I have an engine coolant temperature monitor via my smartphone app.

 

Warmer today, 42F returning home and about the same on the way to work.
Total 0.89 Gasoline used for the 89 mile commute (and one full ~ 6.3 kWh battery charge, courtesy of my home PV.)

100 mpg again

 

50 degrees here today but we are getting slammed tonight. Ice, then snow, then blizzard winds and back to sub zero days. I'm going to stay home with Prime in the garage nice and warm.

 

Which app are you using?

 

Torque

 

Minnesota Prime driving...

 

Question is: in such cold weather conditions, MPG wise would it better to switch in HV mode immediately after start of the car, or let HSD to manage the available sources of energy as it prefere?

I am asking because there is (or there should be) a substantial difference between HV mode, and "fake" EV mode: at costant speed in HV mode, ICE and MG2 basically spin the wheels, while MG1 basically starts ICE and (if necessary) charge the traction battery propelled by ICE.

In EV "fake" mode, with a full traction battery, I reckon that MG1 and MG2 spin the wheels, while ICE idles just to warm the coolant and the cabin. Which looks like a waste of energy...