Winter driving too cold weather MPG down

Your videos are a treat!

It is clear though that the ICE is never adequately warming up. In your shoes I would drive EV out of the neighborhood to not add Nox to the air, switch to HV for ~ 10 miles until the ICE is nice and toasty and some ICE waste heat is available for cabin heating at ~ 180F, and then EV the remainder to work with cabin heating off but perhaps heat seating on.

I'd expect 100 mpg for the work commute, and of course more as winter passes.

 

Pull CAT data to confirm that. You'll discover it's quite a bit hotter than the coolant, enough to properly cleanse emissions. Also, don't forget that there's a trap to collect & purge when conditions are right.

 

The sonar will trigger a warning if you are in motion and something is sensed. Pulling up too close to the vehicle in front of you will do it, like at the drive-thru... which it did... but then ends if that object continues moving. Of course, if you stay that close it will keep beeping. That's mighty close though. Most people don't like breathing fumes anyway.

As for that cross-traffic alert, it was accurate. There was indeed a moving vehicle driving behind me as a backed up. With that, you don't have to be in motion. It picks up other vehicles & people moving... a very handy feature in parking lots.

 

Well winter-blended fuel and winter tires will bring down your fuel economy compared to summer.
Down a little...

For example, this morning my 7.7 mile sunny commute to work just rising above the freezing point, I had to use the defrosters for just a moment. At the home-work endpoints, battery % was between 25% and 26%, so essentially little change in battery SOC. I have Hakka R2s at around 45psi.

52.3 mpg to work
67.9 mpg from work.
60.1 mpg Average

*scratches chin - can't imagine what I'm doing wrong...*

 

When the front windshield defroster is activated from the buttons to the left of the display, the Prime will start its internal combustion engine to produce a lot of warm air rapidly. The engine will then run for enough time to warm up its pollution controls even if you turn the defroster off.

I have discovered that under most circumstances, I really don't need that blast of hot air and that simple air circulation will adequately clear fog on the inside of the windshield. This can be done by using the fan control on the touch screen. Once the windshield is clear, the fan can be turned off by touching "OFF" on the screen.




Of course, if the fogging is happening on the outside of the windshield, and the windshield wipers don't clear your view, you really need to use the engine to heat the windshield glass.

Note: The rear windshield defroster/defogger operates using electric heat from the grid embedded inside the glass and turning it on or off will have no effect on the internal combustion engine.

 

Good advice!
I do two additional things:

1. Rainx treatments on the inside of the window
2. A pretty high percentage Isoprop solution in the windshield wiper fluid

 

Old Bear I couldn’t help but smirk at your detailed reply to my facetious remark that on my morning commute, my fuel economy was *only* 52.3 mpg. Yes I know that the defroster uses energy and can reduce mpg. This morning trip to work, similar travel conditions except for a light rain and no defroster use. Only managed 56.3 mpg. Would have been higher if a traffic light didn’t cut me off forcing me to brake.

 

I'm in no position to judge mpg. Since getting the Prime last August, the only gas we've used for transport was a weekend away in October on Cape Cod which is about 90 miles from home each way. The only other gas used has been when the engine was started by the de-fogger.

Even after reading all the various comments here, I'm still not sure if the best thing to do on longer trips is: 1) start out using EV until the battery is depleted and then let the car switch to HV; or, 2) just set the car to HV and let it decide what to do; or, 3) use EV until the battery is mostly depleted and then run in Charge mode for a while before going back to EV.

As a philosopher friend once said to me: "Many things are both unknown and unknowable."

 

Has anyone noticed a drop in post charge EV miles? When purchased in Dec 2016, living in Northeast North Carolina, I received a constant indication of 25 miles available after charging. Since Nov 2017 my post charge available mileage has decreased to 20-22 miles.I would think if it were weather related I would have noticed in 2016-17. Does this sound normal?

 

Yes.

Prius of all generations & types enjoy the efficiency rise brought back by Spring every year.

With the plug-in model, the return of warmth is especially rewarding.