200 Wh/mile to use heater?

[datoda]

What I notice is that when my car stops at a red light and if I have the heater on, I can see that gray/green (consume/regen) line below the speedometer would show some gray, indicating it's using up the juice.

 

[zhu-]

I'll use my heater in addition to seat heater in the winter thank you very much. I am not going to dress like an eskimo to stay warm IN MY CAR! Do you people not use heat in your home as well and just "dress for the weather"? lol

It is actually pretty funny to imagine people sitting in the cold with one of the most advanced cars in the world. I still have fewer than 500 miles on mine so still learning and experimenting with its efficiency limits. I'm sure once I'm passed this phase I'd have the climate control always on like in any other car.

 

[BobAbooey]

It is actually pretty funny to imagine people sitting in the cold with one of the most advanced cars in the world. I still have fewer than 500 miles on mine so still learning and experimenting with its efficiency limits. I'm sure once I'm passed this phase I'd have the climate control always on like in any other car.

I’ll never sit in a cold car to save money or miles.... I’ll go back to an ice car before that.

 

[mswlogo]

If you have a reasonable commute just leave it in Auto and plug in every night. You're electricity cost will only go up a cent or two per mile. It is also amazing how many owners of a $60 K car don't have garages up north. I lived up north for 42 years and would never dream of having a dwelling without an attached garage ( or of living in a city ). Your results may vary.

You also probably don't pay what we pay in electricity. 0.23/kwh with no off peak.

200 wh/mi for heat adds up way more than 0.01 per mile.

A car that gets a crappy 20 mpg runs around 0.15 per mile.
200 wh/mi of heat alone is 0.05 per mile that's a LOT in my book (1/3 the cost to run a low mpg ICE).

Considering the RWD car runs nearly 200 wh/mi, doubling your energy usage for heat is huge.

I think once the cabin is warmed up, it's typically more like 100 wh/mi, but it does depend on how cold it is. At 0F and 75mph heat could go up to 200 wh/mi (depending on settings).

My MPGe on the car in winter driving is probably close to 40-50 MPGe

There are many exclusive areas that have no garages especially closer to the city. I have an attached garage and to be honest I can't imagine owning a Tesla in the north without one. Because it would even be way worse than I'm seeing WITH an insulated attached garage.

HVAC Auto stinks.

I have been playing around with settings a lot, this is what I came up with.

Manual Mode:

A/C: Off
Window Blower: Off
Front Blower: On
Floor Blower: On
Recirculate: On
Fan: Usually 3-5

This runs real good energy wise. BUT if you have to many passengers OR it's too cold you WILL fog up.
If you fog up (Blast for a Minute with Defrost HIGH) then turn on A/C to maintain.

Turning on A/C to keep humidity down costs juice but not as much as heating outside air (Recirculate Off).

If you still can't prevent fogging then you have to turn Recirculate Off and at that point you can turn A/C off too (don't try to dehumidify outside air). And you might have to turn Window Blower on too to maintain (to warm windshield and evaporate the fog). But that will use a lot of juice when it's cold (but you may have no choice).

It depends on outside temperature, dew point and how much humidity you are generating in the car what settings you can get away with.

The key is, if you can run with Recirculate ON you save a ton of heat.
And you often can. I got 250 wh/mi (on my short commute, which is worst case) with first set of settings above and it didn't fog up.
But it wasn't extremely cold today (but I did need heat). Only one mammal.

If I leave Window Blower: On it will sometimes fog up faster blowing humid air (from humans and other mammals) onto the cold windshield.

If I was in Auto it would have been 350 wh/mi or more.

Also it's not just about cost per mile, it's also range, how many stops you need to make and making it to your next charge point.

Heat makes a HUGE difference and how you manage it can make a huge difference too.

P.S. I personally don't like seat heaters in place of cabin heat. But if you don't mind go for it and turn cabin heat down.

 

[derotam]

Y


HVAC Auto stinks.

I have been playing around with settings a lot, this is what I came up with.

Manual Mode:

A/C: Off
Window Blower: Off
Front Blower: On
Floor Blower: On
Recirculate: On
Fan: Usually 3-5

This runs real good energy wise. BUT if you have to many passengers OR it's too cold you WILL fog up.
If you fog up (Blast for a Minute with Defrost HIGH) then turn on A/C to maintain.

Turning on A/C to keep humidity down costs juice but not as much as heating outside air (Recirculate Off).

If you still can't prevent fogging then you have to turn Recirculate Off and at that point you can turn A/C off too (don't try to dehumidify outside air). And you might have to turn Window Blower on too to maintain (to warm windshield and evaporate the fog). But that will use a lot of juice when it's cold (but you may have no choice).

It depends on outside temperature, dew point and how much humidity you are generating in the car what settings you can get away with.

The key is, if you can run with Recirculate ON you save a ton of heat.
And you often can. I got 250 wh/mi (on my short commute, which is worst case) with first set of settings above and it didn't fog up.
But it wasn't extremely cold today (but I did need heat). Only one mammal.

If I leave Window Blower: On it will sometimes fog up faster blowing humid air (from humans and other mammals) onto the cold windshield.

If I was in Auto it would have been 350 wh/mi or more.

Also it's not just about cost per mile, it's also range, how many stops you need to make and making it to your next charge point.

Heat makes a HUGE difference and how you manage it can make a huge difference too.

P.S. I personally don't like seat heaters in place of cabin heat. But if you don't mind go for it and turn cabin heat down.

As of 46.2 you can do all those manual settings(except for forcing window blower off) in Auto. Before, as soon as you hit recirculate the system went into manual but not anymore.

Obviously YMMV based on temp, dew point, etc, but I leave mine on Auto with Recirculate. The A/C on kept my fogging at bay this morning and over my 45min 30 mile commute this morning with a non-preheated car, temp set to 68, and outside temp of I think 34, I averaged 238Wh/mile.

And at 75mph wouldn't the ~4.6kW heater only cause about 61 Wh/mile load if it is running full out the whole time? For 200Wh/mile you would be have to be going about 23mph.

 

[SageBrush]

For 200Wh/mile you would be have to be going about 23mph.

At 232 mph the heating load would add 4600/232 Wh/mile.

It makes for an interesting question how to minimize winter Wh/mile since faster speeds increase aero losses per mile while reducing heating losses per mile.

 

[derotam]

At 232 mph the heating load would add 4600/232 Wh/mile.

It makes for an interesting question how to minimize winter Wh/mile since faster speeds increase aero losses per mile while reducing heating losses per mile.

And what is the purpose of talking about 232mph?

 

[JeffK]

And what is the purpose of talking about 232mph?

That's the speed at which you travel back in time. 88 mph is only in the movies.

 

[chronopc]

That's the speed at which you travel back in time. 88 mph is only in the movies.

I've only managed to go forward in time. Must be doing something wrong.

 

[PremiumPackage]

I've only read like half the posts here but just to reiterate - you people are insane driving around a $60K car with no heat on. Just run the damn heater. I will admit to having notched it down to like 62 when I'm trying to goose range a bit, but turning it off? FOH. Also note I live in MN, so leaving the heater off means something different me than to you.

 

[RachH]

I try to run without heat when I do my long work drive. Once or twice I week I have to drive 230 miles (AWD 19") before I reach a charger. I run the heat up hot (78%) for about 30 minutes before leaving to be sure it is warm enough, and have the battery charged to 100%. When I leave I cut the heat and just use the seat warmer and drive no faster than 70MPH. Can do it with about 10% left when I arrive at the next charger. When I got the car and had to use the AC, just charging to 100 and limiting speed to 75 was enough to make it.

But, when Tesla puts their promised supercharger (was listed as coming in 2018, but hopefully they get it done in 2019) along the route I will no longer do all that, but will just charge to 90% and crank the heat and enjoy it like the luxury car it is supposed to be!

Do you have the AWD 19" Long Range? That doesn't seem right that you can only go 230 miles (starting at 100% and ending with 10%). Does the heat use that much?!?

 

[JeffK]

Do you have the AWD 19" Long Range? That doesn't seem right that you can only go 230 miles (starting at 100% and ending with 10%). Does the heat use that much?!?

He said it was AWD/19s yes and he also said he turned the heat off in order to get that.

I see similar, if not less, range with the Performance version on 20s at those speeds and that distance. With heat on, there's no way I could make 230 miles.

 

[PremiumPackage]

I don't think that's the heater, I think that's overall coldness reducing battery performance, combined with highway driving. At 70 Mph in 25 degree weather, with little braking for regen, I'll only get about 210 miles of range on a 100-10% basis.

 

[navguy12]

The HVAC system running flat out is something like 8-10kW in the Model S, that's with full heater plus AC drying the air. That's roughly what the Model 3 is, too, although I have only seen approximations so far and accounting for how motor unit is [assumed to be] used for bringing up the battery pack heat makes it kinda tricky to separate out the HVAC and everything. But that's not what get used outside of the first part of your trip unless you're in an extreme situation.

Once your cabin reaches steady-state it can cut back quite a bit, it just has to replenish what the vehicle loses minus what the occupants generate, plus manage the moisture the occupants generate (primarily via their breath). That is partially influenced by how fast you're traveling as air passing over will draw heat off the outside of the vehicle faster. So even though time and outside temp are the prime factors, that increased heat loss rate will partially offset the speed and traveling at 2hrs at 80mph versus 2hrs at 30mph won't be the same.

I have an meter on the circuit feeding my Tesla Wall Connector (set to 48 amp on 60 amp circuit).

The most I have seen the heater pull (with no charging going on) is around 6.5 kW.

 

[mike123abc]

I have an meter on the circuit feeding my Tesla Wall Connector (set to 48 amp on 60 amp circuit).

The most I have seen the heater pull (with no charging going on) is around 6.5 kW.

That is about 8.5% of the battery per hour. A three hour drive you have run through 25% of the battery heating the cabin. I know it is not running full tilt the entire drive, buy you can see how a 230 mile drive over 3 hours can use a lot of heat juice.... The car is essentially a giant aluminium heat sink with the cold air flowing over it... ICE cars get free heat from the engine, so you just do not notice that they are doing it too.

Do you have the AWD 19" Long Range? That doesn't seem right that you can only go 230 miles (starting at 100% and ending with 10%). Does the heat use that much?!?

Yes AWD & 19" tires. Essentially when it is freezing out the car range drops a lot. I have lost hope that Tesla will build their "Target opening 2018" supercharger halfway through my route this winter. I just hope that next winter they will have it in. Lately when it is below freezing I plan a different route which is only 180 miles between chargers, so no real issues driving the 75MPH speed limit and using heat. But, I have to drive 40 miles out of the way to hit that charger, charge up again then do the route.

Tesla really needs to go fix their tesla.com/findus map and change all their target 2018s to 2019s...

 

[JSPA]

In my 2013 Ford Focus Electric, I used not only lap blankets but heavy duty leg wraps, because nominal range of 65 (where I reliably got 85+ in summer) dropped to 40 in the winter if I used the heat (or even full seat heat). With the tesla 3, I use the blower heat to get to 64 or so, and the seat heat for the rest. Make sure to pre-condition to much warmer temps while plugged in, if you need to stretch the heat. And... a lap blanket still works.

 

[sdrevik]

When I commute In town it’s “HI” all the way baby.

When I go on road on road trips, my plan is to use the seat heater, and bring some toe warmers for my feet.

 

[RachH]

He said it was AWD/19s yes and he also said he turned the heat off in order to get that.

I see similar, if not less, range with the Performance version on 20s at those speeds and that distance. With heat on, there's no way I could make 230 miles.

I thought that was what he said but wanted to make sure.

Call me crazy but why in the world would they advertise the LR to go 310 miles per 100% charge and it not even get close to that?!? Why not give a range?

Mine is also the LR, AWD 19" and I was hoping for more mileage. I also live in CA so don't have the major cold others have described so am getting more range- though not as much as I had hoped.

Love the car though.

 

[Perry]

I'll use my heater in addition to seat heater in the winter thank you very much. I am not going to dress like an eskimo to stay warm IN MY CAR! Do you people not use heat in your home as well and just "dress for the weather"? lol

Yea, I agree. I keep it 80F in my house in the winter so I can walk around in shorts and t-shirt, so yes you better believe I use the heater in the car on "HI" all the time. Weird thing I noticed that unless the heater is on "HI", only lukewarm air, which is kind of on the cold side, comes out even when set to 80F. So the only way to get medium heat is to set to "HI" and keep the fan on the lowest setting but I bet that uses a lot of energy which I am fine with. If you can't have comfort then what's the point of a 75K car.

 

[Perry]

What is the obsession with low Wh/mile? Electricity is about a third the cost of gas or less. Did anyone go to these extremes in their previous ICE car ownership where it really mattered? How about seeing how high can we get the Wh/mile. My life time average is 480Wh/mile but I am trying to go for a 500+ record.