4th generation coming 2015!

Ah, OK, do you measure MPGe from the wall to tank to wheels?
Lifetime average MPGe for our 85kWh Model S would be 33.7kWh/gallon x .327 Wh/mile= 103 MPGe.
From the wall, closer to 88 MPGe. EPA is 89 mpge.

For our Prius, I averaged 52mpg in the summer, 42mpg in the winter.

For our new 70D the EPA number is 101 MPGe. I expect to average about 10% better efficiency than in our 85.

 

From the wall so charging loss is included. That's what EPA use in their figure.

 

Then I am about dead on their 89 MPGe figure with the 85 and expect to do a little better than the 101 with the 70D.

 

the heat pump uses less power than the resistant heater, significantly so.

It is however very slightly less efficient in the summer for AC use vs the AC on the original Leaf.

Either way the power draw isn't that bad in the summer, and the winter draw is highly variable.

If you zoom in on the graph you'll notice the heat pump is still more efficient down to about -13F. and in fact gives the biggest gains between -13F and 25F. As in it really does work well even below freezing.

 

toyota bagged the pip heat pump due to cost, i wonder if nissan came up with better and cheaper?

 

It is much more efficient, but in the winter it only has the heat in the freezing air, and maybe inverter coolant, to heat the cabin with.

Likely not. It is just without an ICE for waste heat, a heat pump is worth the extra cost on a BEV.

 

Like all my comments, I am no expert on the subject of automobile heat pumps either.

Help me understand: In my home, the heat-pump is a good year-round solution if the house is maintained at a near uniform temperature. But come into a cold house and raise the heat more than about 2 degree increments, the electrical resistant heaters come on, and the cost go up.

Now the cabin of a car is much different. Sitting outside while you are at work, or a ballgame, or whatever, the interior will be cold when you return. In many instances, you will be home long before the heat-pump warms the interior to a comfortable level without supplemental resistant heating. Isn't that correct?

 

seems like it should be. would be interesting to take one for a spin in winter. maybe if you preheat the cabin while plugged in, it works like your home.

that's how my a/c works, the opposite of a heat pump, but if i let my house get too hot before turning it on, it takes forever to get comfortable.

 

The two degree limit is not necessarily a limit of the heat pump, but of your overall HVAC system.
Also keep in mind the volume of air being heated, or cooled, in a car is tiny compared to the volume of air in a house.

The heat pump can warm, or cool that space pretty darn quickly, and it doesn't require the car to warm up.

I'm not sure why the resistance heaters in your house turn on so quickly. You may want to ask your HVAC guys why that is the case. You may be able to pick up some efficiency pretty easily if that can be changed.

 

I am not sure if the following news have been posted somewhere on PriusChat before, but referring to an older post in this thread (see above), there really seems to be the possibility that a Gen4 Prius SUV will extend the lineup:

Toyota Prius SUV Reportedly in Development

What do you think?
Personally I don't care since I don't like SUVs; but what I really dislike is the diesel option. An absolute no-go from my point of view.

 

There is a much larger volume of air to heat in a house. A car cabin is around 100 cu.ft., a 10x10 room is eight times that.

 

True. But a house is a hell of a lot better insulated. Plus, look at the percentage of the exterior of a car that is glass. There is tremendous heat loss from a car on a cold day, and heat gain on a hot day. A house can remain fairly comfortable for a number of hours.

 

and each has an appropriately sized appliance.

 

Yes, a house does have better insulation.
However, that is overwhelmed by the volume of air.
The average American house is, from memory, about 2500 square feet. That is about 20,000 cubic feet.
Add to that inefficiencies in a larger HVAC system (air duct leakage, bends in ductwork, etc)
So warming a house 10 degrees costs (20,000 cubic feet)/(100 cubic feet) 200 times more energy.
Even if the house's insulation is five times as good, that is still 40 times more energy.

Of course, you could also try it for yourself. Next winter, go for a test drive and see for yourself

 

I like seeing more efficient choices out there in each vehicle category. I wouldn't buy it myself, but if it fills a void, so much the better.

 

Not the same.

In a home the heat is transferred air to pipe to air, in all practical purposes it flows straight into the living area at full force.

In the car the heat pump is heating a tank of fluid not air and the heat pump can heat that at a steady rate within it's efficiency curve until it is hotter than the desired temp and then a system can transfer the heat from the tank to another pipe and then to air.

It's also a matter of scale. The car space is so small in size compared to the power of the heat pump it can do it very fast in comparison to an entire house. So taking a house of 20,000 cubic feet and comparing it to 200 cubic feet in a car the challenge to the heat pump is 100 times easier to do.

 

All I was doing was trying to generate some thought and discussion while we sit around waiting.

 

Absolutely, it was an excellent question to ask.

You raised the comparison to a house, and people are discussing why there is such a big difference.

 

I don't know why I even read this thread, other than I own a 2010 and I am interested in the technology. I am pretty sure I will not purchase a G4. I own 2 cars now, and will replace both with a new, upscale sedan. But I want a hybrid, and hope that Toyota will apply the new technology to the Lexus? Or the Avalon? I cannot imagine they would not.

Interestingly (at least for me) I like an Acura. I visited the showroom, spoke with a salesman about their hybrid. Acura uses the hybrid technology to improve performance, not to improve milage. No thanks.

 

Lexus HAS hybrids now.
As they have in the past, I am sure Toyota will use the technology they spearhead for the Prius and use it elsewhere, such as Lexus.

With the Lexus though, you won't get as much efficiency as you will in the Prius. That is just a matter of fact when you use gasoline to power a car.