What? Using the heater does not affect range in a gas powered car.
It typically does (though not as much as the chiller would).
There's two costs to using the heater:
1. The electricity to power the fan comes from the engine. I'm not sure how much of an impact this actually is (depends on the power the fan needs) but there's something there.
2. The heat from the heater comes from the engine block, which cools the engine. On cold days (<15 F) this can have a huge impact on the engine's temperature and will often cool the engine well below it's most efficient operating temperature.
First, the power the run the fan is minuscule. On the order of a few Watts. Maybe a few tens of Watts at most. It's an order of magnitude less than what is needed to run seat heaters (and those have almost no measurable effect on a Model S's range, which is why "range mode" uses seat heat in favor of air conditioning). The energy use you're talking about is enough to move the car an extra few hundred feet after a multi-hundred mile drive.
Second, every ICE has a thermostat on the radiator. It greatly reduces coolant flow to the radiator when the car is warming up, or any other time that the coolant is below optimal temperature. I spent many years in the northern (continental) United States and never encountered a situation where the coolant temperature gauge on an ICE car failed to show normal operating temperature after 10-20 minutes of warm-up time.
The cold-weather fuel economy difference in a conventional car mostly comes down to greater air density.
In an EV, heat must be generated at a very high energy expense. You can play with the mileage range estimator on Tesla's website. For the largest capacity (85 kWh) batter, heat knocks range down by about 50 miles. Depending on conditions, at 55 MPH, you're talking 350 to 300 or so with heat at 32F. A gasoline powered ICE will likely actually get slightly higher performance due to greater thermal gas expansion at low temperatures, and lower overall cooling demand: while running the cab heater doesn't consume much power, spinning the radiator fan does, and can usually be avoided in cold weather.
Go further North. I have not seen the temperature gauge on my car move since about October, and I have a huge piece of cardboard blocking the entire radiator to stop air flow.
This won't make any difference unless the thermostat is open. If your temperature gauge is on "cold", you're not even close to the point where the thermostat will open if it's operating normally. Which raises the question: have you had your thermostat checked to make sure it's not stuck open?
Actually, it makes a huge difference as it stops an enormous amount of very cold air going through/around the radiator onto the engine. Everyone up here does it, else cars would not be warm enough to run properly.
> Have you had your thermostat checked to make sure it's not stuck open?
Of course. Everything works great in summer when it's ~+25C
To give you a better understanding of how cold -50C actually is, I can drive for an hour, get out and put my hand directly on the exhaust manifold of my 4-cyl East-West engine (exhaust at front for cooling) and it's only just warm to the touch.
It's cold. Very cold.
Ah, that explains it. :-) I used to do cold weather testing when I worked as an automotive engineer; the coldest we ever tested at was -30 C, and there were plenty of test vehicles that didn't fully warm up at that temperature.
The extra fuel comes automatically because modern EFI (electronic fuel injection) motors use several sensors in a feedback loop to ensure that the air:fuel ratio is 14.7:1
There is an air temp sensor and compensation that adds roughly 1% fuel for every 10F drop in temperature. Then the oxygen sensor in the exhaust system measures whether combustion is hitting the 14.7:1 target and adds or subtracts fuel accordingly.
The sparse atmosphere robs the engine of power, just as it reduces your body's ability to gather oxygen.
The engine's preferred operating temperature is much higher than any reasonable air temperature, and until that point is reached the engine oil will be less lubricative and the fuel (particularly in the case of diesel) less inclined to combust. It will naturally take longer to reach that preferred temperature when it is cold outside, because not only is the air cold but the engine is also this big lump of cold metal, absorbing the heat of combustion and pulling it away from the cylinder where it is needed.
Personally, high altitude driving helps my fuel economy -- I would speculate that it's due to decreased air resistance and the lack of power forcing me to drive a little more conservatively.
1) The nominal amount of electricity used by a heater blower motor is not going to measurably affect the range of your trip (this is most likely the same for the Tesla)
2) The heat from the engine block is waste heat from the relatively inefficient combustion process. This heat has to be actively dissipated in most driving conditions (typically even in winter). It is essentially free to pipe this heat into the cabin. Now contrast this with the Tesla's 400 electrical resistance heater, which has to directly compromise range to generate cabin heat.
My mitsubishi mini-split: 1. Can produce it's full BTU load all the way down to 5F, and 75% BTU load down to -13F. 2. Doesn't bother to blow air until it's warm :)
They aren't even that much larger than a resistance based coil system (though I could imagine the model S may not be able to fit them)
The fan practically never runs in cold weather. The only time it's needed is in hot weather, when you're stopped or at low speed and there's not enough airflow over the radiator and/or condenser. In cold weather the thermostat controls engine temperature, not the radiator, so the fan never gets told to turn on.
That being said the amount of electricity, and thus the load on the belt, to run the fan is very very tiny compared to the energy required to heat the air. In an ICE, the heat energy is literally free. You were going to dump it anyway, might as well be into the cabin.
Since engine speeds vary greatly, having a dumb alternator that provided power scaled in proportion to RPM would be a disaster.
The alternator (or really any electric generator) has a magnetic field, and a lot of coiled up wire. Moving the wire thru the field generates electricity, the faster the wire moves the higher the voltage is. But the more current is moving thru the wire (more load, more things using the electricity), the more it pushes back against the magnetic field (because that current in the wire generates its own field) and so the harder it is to make it move.
www.sae.org/events/aars/presentations/2004-hill.pdf
Interestingly, the graphs on pages 14 and 15 of the linked report don't appear to support your point. That is, the green curve is strictly less than the blue curve at all investigated speeds.