Warming up the car in winter

The coolant in a GenIII is heated from the ICE, the exhaust system and the EGR cooler. Since it has an electric water pump, the coolant can be circulated totally independent of the ICE. With this, warmed coolant can still be pumped through the heater core even though the ICE isn't running.

 

What seems logical isn't always. Note your mpg before going into ready. Now run your engine, I don't care how long or how you do it. Now without moving your car, did your mileage go up or down? If you have a commute where you know you must drive in HV, then start out in HV and drive until the engine is not running often. If now to your advantage, switch over EV . That scenario will give you the best mpg. For Winter.

 

Sounds really convincing, now, HOW does one get heat or even air out of the windshield vents for defogging W/O turning on the defroster button OR the AC? Try it, you can't do it? Read my post on Winter Driving. Actually Johns post.

 

Thanks for the pointer to that video. I didn't know of that video but I was present at that event and saw the display.

I guess it makes some sense. I briefly met the world famous Wayne Gerdes there.

 

Maybe the OP is referring to the estimated EV range drop when you turn on the heat

Mike

 

Having a scangauge here would be helpful.

Once the ICE heats up to 130F, you can turn on the heater without the ICE firing up. Once the temp drops to 118, it will fire up again.

So, to maximize mpg, I don't turn my heat or defroster on, if I can help it, until I reach 130. If I see it dipping to 118 when I am stuck in traffic, I turn it off for a while until I get back up to temp.

Without the scanguage, the engine temp is a mystery.

 

(I have no Gen 3.)

I've heard that on Gen 3 Prius, putting it on Eco mode changes the ICE startup threshold down to 110 F. I have no means of verifying.

In Gen 2 (which has no mode selection buttons), if heat is on FWT (Fahrenheit water temp) must be >146 F to prevent ICE from starting up.

Yep, w/o Scangauage II or some other means of monitoring engine/coolant temp, it is a mystery.

 

People, I think we are all a little narcotic about gas millage. If you have a 7 mile commute and want to be warm just turn On The heat, the ice will run for 5 minutes to get up to temp. So what? How much has are you really going to burn?

With the pip you are saving so much money over 95% of the cars on the road. Be warm be happy. Or use the seat Warner's, Either way no big deal

 

You're missing the point. Some people like big numbers. It's fun in a video game sort of way.

 

exactly. plus, we're trying to understand what the op is encountering.

 

The heat comes from the ice.

 

Or saying.

 

right.

 

You mean without using the windshield/floor mode setting?

 

Any button pushed will not enable you to get air flowing out of the defrost vents except, the defrost button and the AC button. Your comment before as to heat source from inverter coolant is probably correct. I have had no problem with regular dash vents, only the with the windshield defog.

 

The button I mentioned above allows airflow to the windshield while on the highway, with the fan off if you want to do that.
I didn't reference the inverter for a heat source. The exhaust pipe has a water jacket to heat up the engine coolant and the EGR cooler has a water jacket to cool the exhaust, so both along with the ICE heat up the coolant to give the cabin heat. The inverter coolant isn't involved.

 

I'm with you, I want heat in the car.

 

the windshield/floor mode on air setting works fine for defogging/defrosting the windshield. are 'defrost vents' different?

 

As Bisco and El Dobro state, you don't have to press the Front Windshield Defogger button that also starts the ICE.
As long as the Temp Control buttons have selected a Temp Setting of LO, you can just press the Air Outlets button. It directs the air flow with or without the fan and doesn't require the ICE. If you raise the Temp Setting, then the ICE will start.

When you first start the PIP, you have 10 seconds to lower the Temp Control to LO and the ICE won't start. If you start the PIP and the Temp Control is not in LO, the ICE will start after 10 seconds.

 

Ok strike inverter. How does heat get into the cabin if the ICE has not started. Water jacket on exhaust is useless w/o engine. The both that you mention are dependent on the engine running. I have not gone out on the highway to check airflow with my telltale. If it is there it is definitely minimal. But I wil check.