Is the Mach-E really 7 years behind Tesla?

[Nak]

Folks, Sandy Munro knows this stuff far better than I do and has videos explaining it in depth. If you want to understand the octovalve and the heat pump, watch Sandy's video. BTW, in case you were wondering Sandy IS NOT a Tesla fan boy. In fact, his video on the Model 3 was not complimentary at all. He is one of the renowned experts in auto manufacturing and calls them like he sees them. Car companies spend many tens of thousands of dollars to get his input. You can get it for free.

I have watched all of his Model Y teardown videos, and I can't wait to watch his Mach-e tear down videos.

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[Jolteon]

I don't think anyone is saying a heat pump is magical in all conditions.

When the car is cold soaked, it will take energy to warm up the Y or any heat pump vehicle.

The difference is that with preconditioning in an EV, that largely doesn't matter for range since the car is already warm when you start driving. The heat pump is all about extending driving range in cold temperatures.

If long distance cold weather drives aren't your priority, then it will never be an advantage. But as someone who takes long road trips at all times of year, I would love the Mach-E to have a heat pump.

The heat pump is magical because unlike the Mach-E's PTC, there are many operating modes where the COP is above 1, and no PTC can ever get above 1.

 

[Woeo]

MME EPA numbers aren't out yet, but Ford's estimates are surely pretty close... 270 miles projected on the AWD ER, 98.8 kWh full battery (88 usable). 270 / 88 = 3.07 miles/kWh.

Model Y AWD LR 316 miles range, 75 kWh full battery (est. ~72 usable). 316 / 72 = 4.39 miles/kWh.

Even if you tweak the usable battery up for the MY, and tweak the MME EPA range up a little, it's still not close.

Except that Tesla games the EPA system [as do many ICE manufacturers]. Darren Palmer has been hinting that Ford won't play that game with the MME. Promising MME EPA numbers will be close to real world. The Korean brands are taking that approach as well.

Inside EVs published a chart in April showing results compiled by AutoCar in it's real world testing..

1. Hyundai Kona Electric, 259 miles (258 EPA miles)
2. Jaguar I-Pace, 253 miles (234 EPA miles)
2. Kia Niro EV, 253 miles (239 EPA miles)
4. Tesla Model 3 Performance, 239 miles (299 EPA miles)
5. Tesla Model X P100D, 233 miles (289 EPA miles)
6. Nissan LEAF e+, 217 miles (226 EPA miles)
7. Mercedes-Benz EQC, 208 miles (259 WLTP miles - anticipated 220 EPA miles)
8. Tesla Model S 75kWh, 204 miles (259 EPA miles)
9. Audi e-tron, 196 miles (204 EPA miles)
10. Renault ZOE R135, 192 miles (238 WLTP miles)
11. Tesla Model 3 Standard Range Plus, 181 miles (250 EPA miles)
12. BMW i3 120Ah, 165 miles (153 EPA miles)

All four Tesla's tested claim 125% [or more] of their AutoCar real range as their EPA range. If the same is true for MY AWD LR we should expect 252 miles on the AutoCar test.

It the MME comes in near EPA numbers total range might be a win for Ford.

 

[Jolteon]

Correct, for those first 10 minutes on those drives it will be less efficient, but just about as efficient as a PTC.

But that's ignoring what the heat pump is *for* in the first place, range while actually driving. And that's where the heat pump is a clear winner.

The Model Y's solution is elegant because it's roughly the same cost as a non-heat pump PTC system that the Model 3 has, which is why they're rolling it into the 3 now - they get more range for the same money.

 

[JCHLi]

Correct, for those first 10 minutes on those drives it will be less efficient, but just about as efficient as a PTC.

But that's ignoring what the heat pump is *for* in the first place, range while actually driving. And that's where the heat pump is a clear winner.

The Model Y's solution is elegant because it's roughly the same cost as a non-heat pump PTC system that the Model 3 has, which is why they're rolling it into the 3 now - they get more range for the same money.

So in that first ten minutes is everyone sitting in a cold vehicle waiting for it to warm up? I know for my gas vehicles I use the remote start, but that starts the engine and wastes gas (less range)

How does that work with the heat pump, where is it getting the heat from prior to the motor(s) running? I suppose the atmosphere, but let's say it is -5F... Is there some type of backup?

 

[Jolteon]

They hadn't invented it until the Model Y. It's novel enough that they got a patent on their system.

They hadn't used normal heat pumps before because those cost too much money. This allowed them to get the heat pump for cheap bc of their invention.

 

[Jolteon]

So in that first ten minutes is everyone sitting in a cold vehicle waiting for it to warm up? I know for my gas vehicles I use the remote start, but that starts the engine and wastes gas (less range)

How does that work with the heat pump, where is it getting the heat from prior to the motor(s) running? I suppose the atmosphere, but let's say it is -5F... Is there some type of backup?

It runs the drive motors inefficiently to generate extra waste heat.

It does eliminate some of the Model 3's truly instant heat advantages of the air PTC (vs Mach-E's liquid), but that just puts the Y on par with every other car.

 

[JCHLi]

It runs the drive motors inefficiently to generate extra waste heat.

It does eliminate some of the Model 3's truly instant heat advantages of the air PTC (vs Mach-E's liquid), but that just puts the Y on par with every other car.

So how long does it need to run inefficiently to produce the necessary heat to defrost an 1/8" of ice and make the interior tolerable? And when you say it runs the drive motors inefficiently, how is this done, do they crank up the resistance to generate heat?

 

[Jolteon]

So how long does it need to run inefficiently to produce the necessary heat to defrost an 1/8" of ice and make the interior tolerable? And when you say it runs the drive motors inefficiently, how is this done, do they crank up the resistance to generate heat?

I don't own a Model Y so I don't know. I also park indoors so for me that wouldn't necessarily matter even in the winter. I'm more concerned with steady state highway speed winter temperature range which is why I wish Mach-E had a heat pump.

No car's perfect, I've never said any were.

 

[trutolife27]

The heat pump in the Tesla Model Y is able to generate more heat power than what it takes from the car's battery (in most situations). Where is this additional heating power coming from? How does it work? Goal: heat up the car’s cabin when it’s cold. COP (coefficient of performance) = Q (heat put into cabin)/W (work required to generate this heat). COP ~ 1 for more electric heaters. Ex: the 100W of electric power that goes into your space heater from out the wall creates almost 100W of heat.

Tesla’s heat pump has a COP of 3, so for the Tesla to generate 100W of heat inside the cabin, it’s only using 33W of power. Are we breaking the laws of physics? Energy cannot be created or destroyed. Where do the other 67W of heat come from? The outside of the car, by entering the evaporator. A heat pump is a refrigerator running in reverse. 1. A compressor turns a low pressure (P), low temperature (T) gas into a high temp, high P gas 2. This high energy gas enters a condenser where thermal energy of the gas is given to the cabin to raise cabin temp.

As the gas loses energy it condenses into a liquid. 3. The liquid moves through an expansion valve that causes the P to decrease (and T). There’s more volume available to the liquid. 4. The low volume makes the liquid vaporize as there are fewer intermolecular collisions. As the liquid molecules turn into gas, they pull thermal energy from their surroundings (the outside of the car).

In the evaporator we now have a low pressure, low temperature gas that repeats in this cycle. Caveat to heat pumps: heat pump’s COP decreases as the temperature around the evaporator decreases (in colder places, the COP isn’t as great) as the liquid molecules that want to be a gas don’t have as much thermal energy available to them. At -20 degrees C, the COP of the heat pump ~1 (which is the same as normal electric heaters). The fluid that turns from liquid and gas and back again is called refrigerant, and one common example in cars is called R134a.

 

[trutolife27]

This video is dead-on about it. So who was right ?

 

[JCHLi]

I don't own a Model Y so I don't know. I also park indoors so for me that wouldn't necessarily matter even in the winter. I'm more concerned with steady state highway speed winter temperature range which is why I wish Mach-E had a heat pump.

No car's perfect, I've never said any were.

I'm just curious about how it all works in practice. My concern when I hear about this heat pump is reliably. First, if it uses the drive motor inefficiently to produce heat, I worry about the wear and tear on the system. Second, the overall complexity of the system is concerning. If a standalone resistance heater were to go out, it would be a fairly easy and inexpensive fix, if you burn your drive motors up, not so much. If you need to work on a simple AC with one loop, it's a lot simpler compared to one with multiple loops running from the motors, battery, cabin, etc.

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