EV or EV auto

Thank you!!!! I drove in HV b on the thruway this morning and EV in slower roads and averaged 113.5 mpg

 

I'll second that. If I'm on the highway, unless it's a short trip, I'll put it in HV mode. EV is pretty inefficient up at highway speeds, and it gives me EV for when I get off the highway. I'm not sure I hit 113.5mpg, but it was definitely pretty high!

I'll do EV around town, unless I see the battery getting very low, in which case I'll put it on HV to maintain the charge (I try not to let my battery go to 0 or 100).

 

Not to worry. The display just shows the percentage of available charge, not the percentage of actual charge. The system protects the battery so you don't have to. 100% indicated is actually about 83-84% real world charge, for example. I can't remember what it is when it hits zero and puts itself in hybrid mode, but it's obviously not fully discharged or it wouldn't be drivable. I think it's about 14% at that point.

 

Yes, I think I'm being a little too overprotective. I might soften up a bit.

My last couple of cars I've held onto for over 10 years, so I'm hoping to do the same with this, and not have to worry about a battery replacement.

Considering my commutes are very short anyway, it's not too big of a deal either way.

 

Yup. The car is built for driving. My '17 is now almost four years old, it has about 46,000 miles and the battery still takes the full 6.x kWh to do a full charge. No sign yet of any decrease in capacity. And there's a 10-year warranty on your hybrid system. I don't recommend (nor does the owner's manual) letting it sit long term with a fully charged battery, but that's why it has a scheduler. As lots of people on PC like to say, "Just drive it."

 

2022 and still no way to change the default. Even with Carista or any similar application...

 

Nope. The car is designed for lowest possible emissions primarily and secondarily for high fuel economy. That's most reliably accomplished by defaulting to EV if it's available. If you're going on a long trip and want to save the EV range for later, you'll soon learn to hit that selector button as a habit.

 

As I just confirmed today, the default EV mode is sometimes overridden by Toyota's design in extremely cold conditions probably to protect the traction battery. I can't say the same about the extremely hot conditions, but I would not be surprised to find out Toyota has designed to override the EV mode in such conditions as well.

The case in point. Today morning low temp was -6F. My car sat overnight cold-soaked with a full battery charge since yesterday. No charging cord was plugged in and no traction battery heater was turned on. I had set the HVAC in OFF position yesterday before shutting down. This morning, I turned on the car, the engine immediately fired. As I said, no HVAC, no defrost, no heated seat, no headlight. The load on the traction battery was minimal. Yes, the car decided to override the EV mode and start the engine.

The first leg of my trip was 8.12miles. The entire distance was set on the default EV mode but with the engine on. The Eco diary display remained in 0miles/kWh and 0% A/C ratio. The traction battery temp stayed between 10F to 14F. Overall efficiency, 41.03 mpg (all on engine alone on EV mode) 0.0 miles/kWh

After a few hours, I drove off for the second stop 3.3 miles away. By this time the traction battery temp remained at 14F, but I was able to start the car in EV mode without starting the engine. I was able to drive the entire 3.33 miles in EV mode without the engine on. The traction battery temperature has reached 23F at the end of the trip. Overall efficiency, 999.9 mpg reported (all EV mode) 2.8miles/kWh

I run my errands for ~30min then my return to the home trip of 5.23 miles. The car started in EV mode without the engine coming on. The traction battery temp was 23F at the start and only got up to 24F. Although I had no HVAC turned on, on steep hill descent, the engine started and completed the warm-up cycle. Overall efficiency, 124.2 mpg (some with the engine on EV mode) 5.4 miles/kWh

 

I would expect it to override EV in those conditions, but that's kind of a fine-print exception. Most Primes never see weather that cold and those that do rarely see it.

But ...

How the heck did you keep the windshield from frosting over without any HVAC in those temperatures? Hold your breath the whole way?

 

Yeah, I have a few tricks to deal with that.

First, I keep a thermometer/hygrometer on my dash to monitor cabin temp and humidity. When relative humidity is low, there is no worry about fogging up the window. I try to keep the cabin humidity below 70% all the time. For three short trips yesterday, while I was driving (indicated by the red lines in the graph below), the cabin humidity was lower than 60%. Humidity rise takes time (see the lag on the rise after my drive) and with a short trip of less than half-hour with only one passenger, inside window fogging is not a problem.



Second. I have treated inside windows of my car with an anti-fog agent. I use Rain-X anti-fog, but shaving cream would do the same job.

Third. I keep a few bags of desiccant on the dash and cabin. You can buy a reusable type like this. But rice or kitty litter in a small pillowcase or a sock would do the same job. I have been using one with activated charcoal which also acts as a deodorizer like this one. It works great to keep the air clean and prevent musty smells.

Forth. If the front windshield starts to fog up, cracking a window just a little is the quick and easy remedy to get rid of the fog.

Fifth. If it is too cold to crack the window open, then as a last resort, I turn on the HVAC manually set to temp 65F, AC OFF, and the lowest fan setting directed to the front window. With this setting, I can usually keep the EV mode without the engine turning on. BUT, albeit all the efforts, if the car decides to turn on the engine anyway, then I switch ON the front defrost. If the engine is already ON, then there is no reason to waste the good old combustion energy transformed into heat. Most of the energy in the petrol can not be used for propelling the car, so as might as well use it for the comfort of the driver.

BTW, I only did what I did yesterday as a part of my experiment. Normally, when the temp is below 14F outside, my routine practice is to turn on the car and immediately switch to HV mode to start the engine and warm up the cabin using the engine heat and save EV range for later use.

 

Toyota will not use EV mode if the battery is too cold. This is to save your battery.