ECO Mode and Cold Weather Performance

As someone who never owned a GenII, thus has no experience with its cold weather 'features', it takes a few reminders such as this to fully appreciate the GenIII improvements.

 

I have seen this in my own car and concur with the analysis.

 

18°F on the drive in to work today (lower grille totall blocked) with ECO.

55.5 MPG was the displayed result.

That's well beyond any I ever saw with my other Prius.
.

 

28F on the 17 mile drive in today. Lower grill totally blocked, Prius in ECO. Displayed 67MPG. Of course the engine block heater helped. But the car does seem to let you drive in electric at any point after stage 1.

Wayne

 

Never thought of this, but probably right.

 

My 2010 is the first Prius I've owned so I can't compare to the previous gen but I'm surprised at how fast the engine will stop after leaving home. I stop at a light less than a mile from home and only 3-4 minutes after leaving home and the ICE still stops at that light, even with the outside temp cooling down. Sometimes it doesn't stop immediately, but still stops before the light turns green.

The garage helps as it currently stays in the low 50s and in the coldest of winter the garage will still be around 30 while it is below 0 outside. I drove all ECO when I first got the car but now use Normal. I will have to go back to ECO and see the behavior and like the idea of using it in snow.

 

does the engine normally stay on with the heater in NORMAL mode?

i noticed a massive drop in my MPG over the past 3 days that pulled my MPG from my last tank to 43.14 from 50.07 in the tank before, even though driving was the same overall. The only difference was the drop in temps Houston had in the past week. Not sure if that was the exact cause but maybe I should start using ECO mode in cold weather. (I use Normal most of the time)

 

I can't speak to "NORMAL" mode, but what I did find, using PWR Mode causes the ICE to run more in the COLD climate.

When switched over to ECO at any point, the ICE turned off.

So as Tideland stated, I think the ECO plays a big role in the winter FE Numbers....and am going to stick with ECO for a bit to see how the results fair.

In PWR I noticed about 47/48 MPG, in ECO 52MPG

 

I've been running in Eco mode exclusively. It makes it a lot easier to keep the Eco bar to the left, and if you ever need real power, you just have to press the pedal to the metal. The ICE does shut down quicker in Eco, surprisingly, even when it is cold out.

 

I had a drop in displayed mpg this week, after the cold snap hit. I had been running in normal mode, as an experiment, since I never noticed much difference before when running in eco or normal mode. I blame more engine running, to keep the heat up, long past the normal warm-up period. Seemed to make a difference in engine running when I set the temp lower.

 

I drive in ECO all the time so the differences were not as apparent but I agree with the conclusions, this car is better than the Gen2 was in winter.

It's colder this week, 0 to +10 degrees F, so I am anxious to see how it does.

 

And because of this, it will take a bit longer to get the cab up to temperature in cold weather.

 

In stop-and-go driving, ECO mode seems to cycle the engine on when the water temperature goes down to 114F and off when the water temperature goes up to 130F (as per the ScanGauge II), regardless of the heater's fan speed.

Normal mode also seems to cycle the engine on and off between 114F and 130F until you crank up the heater fan speed to maximum. Then the engine stays on until the water temperature hits 148F. I'm not sure what the lower temperature is with the fan running flat out.

 

I hadn't noticed that.

Contrary to what others have been saying, I find that I get 3-4 mpg better in Eco compared to normal. Assuming traffic allows it, it is easier to keep the Eco bar to the left.

Although we have only gone into the mid 30sF, I have barely noticed a 1 mpg drop.

Another thing I have noticed...On a cold start, even though the ICE comes on, if you drive slowly in Eco, the ICE does not rev up. You are driving on battery. I always wondered why folks were saying they got poor mpgs on short trips, while I wasn't. This must be a new feature in the Gen 3.

And I think I've said this before...on a cold start, I am amazed at how soon the ICE will shut down when coming to a stop light....sometimes in less than a mile.

 

Yes I see that also, the sequence is 15 seconds after the Ready light comes on the engine starts and runs for 1 minute. As you observed during that minute it will not provide power to the battery or the wheels at moderate throttle. You can eliminate the 15 second wait by pushing the throttle down (in Park) and releasing it. This starts the engine immediately.

I think we are better off, from a mileage point of view, if we just set in the driveway and don't drive off until that minute is up. If we drive on the battery the engine has to put that energy back in after the minute is up and due to the conversion losses there is a net loss of energy. There are exceptions, for example if you live at the top of a hill and can coast down, or if you have more than 6 bars in the battery.

 

Thanks, I'll try too