CR report on EV range tests

[Nklem]

Then why did the Tesla see the exact same percentage range loss as the Mach-E in mild temps? That implies 50-60 degree range where some cabin heating is required.

So little heat is needed at 50F ambient that the difference did not matter in range. Most car systems are approximately 80% recirc and 20% or less outside air.

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[dml105]

That’s where the heat pumps show their benefit in the cold weather ranges for sure.

But it didn't...

Both the Mach-e and the Tesla lost almost exactly 1/3 of its range in the cold. So, what's the benefit of the heat pump?

 

[andyrross]

I feel like keeping a copy of that graph handy for everyone who asks about range

 

[voxel]

But it didn't...

Both the Mach-e and the Tesla lost almost exactly 1/3 of its range in the cold. So, what's the benefit of the heat pump?

Zero benefit at 16F but as others have said heat pumps shine around 30-40F.

From (I'm a CR subscriber) https://www.consumerreports.org/car...e-affects-electric-vehicle-range-a4873569949/

"On the cold day, the temperature averaged 16° F (-8° C), meaning that considerable energy was needed to keep the cabin comfy and the battery pack in its ideal operating condition. The mild spring day was 65° F (18° C) during most of the drive, and the warm summer day was 85° F (29° C) during the drive. Each test day was clear and sunny."

I've personally pushed for PHEVs in sub freezing climates as the range loss with BEVs is too great.

 

[voxel]

FYI the testing methodology removes temp/wind variables since they were all driven at the same time at the same speed on the same route.

"The cars were taken on the road concurrently and driven on the same 142-mile round trip route of Connecticut Route 2 and I-91. We used adaptive cruise control set to 70 mph and the widest gap to prevent any aerodynamic trailing effect or sudden decelerations and accelerations due to surrounding traffic. The regenerative braking mode was set to its lowest setting for each car. We paused for 10 minutes with the cars off at the midpoint. "

 

[Nklem]

But it didn't...

Both the Mach-e and the Tesla lost almost exactly 1/3 of its range in the cold. So, what's the benefit of the heat pump?

The Y has a battery that is 75 kwh compared to the 88 or 91 in the Mach e. So the Y did 2.26 mi/kWh at 16F and the Mach E did 1.93 mi/kWh. Correct, a 38% loss of each. In the summer, Y did 3.63 mi/kWh where the Mach E did 3.11.

The heat pump Tesla uses May have a 1:1 performance at 16F. The reviews I have seen touting the Tesla heat pump seem to all be at 35-45F, which this tells us why.

As noted above, if it was 25-45 ambient, there more than likely would have been a difference, but in reality that difference is 10-20 miles.

Is that worth the expense, complexity and weight? IDK.

Here is the Tesla heat pump efficiency curve from their Patent.

 

[SWO]

So much for that vaunted heat pump.

That was my first reaction when seeing the numbers as well. I've always suspected this was the case. Lots of added complexity for little gain.

 

[SWO]

True. Just depends on what means more to each person: range or efficiency.

Personally I care more about actual range, which allows me to go more places (because there's long gaps on many routes), and reduces my odds of getting stranded.

Teslas have quite a bit more vampire drain than the Mach-E. Would be interesting to see if the Tesla is really more efficient if you include the few percent it loses every day just sitting in the driveway....

 

[tannerk89]

The Y has a battery that is 75 kwh compared to the 88 or 91 in the Mach e. So the Y did 2.26 mi/kWh at 16F and the Mach E did 1.93 mi/kWh. Correct, a 38% loss of each. In the summer, Y did 3.63 mi/kWh where the Mach E did 3.11.

The heat pump Tesla uses May have a 1:1 performance at 16F. The reviews I have seen touting the Tesla heat pump seem to all be at 35-45F, which this tells us why.

I have tried to find the Tesla specs, but of course it’s a secret. As noted above, if it was 25-45 ambient, there more than likely would have been a difference, but in reality that difference is 10-20 miles. Is that worth the expense, complexity and weight? IDK.

The Mach-E is less efficient in all climate conditions - but the range loss due to this cold test is the same for both, at the very least leading the reader to believe heat pump/Tesla is not a huge benefit over other manufacturers.

I probably wouldn’t see any benefit because with preconditioning and being garage kept my heat barely ever turns on to warm up the car even when it’s cold. All the numbers match up from what I’ve experienced.

 

[Raymondjram]

Getting ready for the flood of "where did my range go" posts this winter, this should be sticky.

according to CR, if I read this right,
Cold =16 degrees
Mild = 50 degrees
Warm = 80 degrees

A reminder that "cold" means different things to different people.

Cold is any temperature that is close or below freezing. Warm is close to the human body temperature (96), and hot is above that.

 

[RickMachE]

I've personally pushed for PHEVs in sub freezing climates as the range loss with BEVs is too great.

Our Fusion PHEV got 21 miles in warm weather, 12 or 13 in cold. Same type of loss. Only reason it made sense was it was a commuting car and with rebates it was cheaper than a Fusion gas equivalent or the Fusion Hybrid.

A PHEV needs an electric range of 75+ IMO.

 

[Nklem]

Our Fusion PHEV got 21 miles in warm weather, 12 or 13 in cold. Same type of loss. Only reason it made sense was it was a commuting car and with rebates it was cheaper than a Fusion gas equivalent or the Fusion Hybrid.

A PHEV needs an electric range of 75+ IMO.

I agree. That's why the Rav 4 is so popular, it has the highest electric range yet but still not 75 miles.

 

[voxel]

Our Fusion PHEV got 21 miles in warm weather, 12 or 13 in cold. Same type of loss. Only reason it made sense was it was a commuting car and with rebates it was cheaper than a Fusion gas equivalent or the Fusion Hybrid.

A PHEV needs an electric range of 75+ IMO.

Right but gas range doesn't drop 30% in winter.

 

[RickMachE]

Right but gas range doesn't drop 30% in winter.

Gas range does drop in winter. Both from the cold, and from winter gas. My 18-19 miles per gallon on my F-150 drops to 14-15. While maybe not 30%, most people are clueless about winter MPG. In fact, most go "what's winter gas, we don't have that here in ____".

 

[dml105]

Gas range does drop in winter. Both from the cold, and from winter gas. My 18-19 miles per gallon on my F-150 drops to 14-15. While maybe not 30%, most people are clueless about winter MPG. In fact, most go "what's winter gas, we don't have that here in ____".

Right.

"Range" just isn't something ICE owners have top of mind. MPG, yes. Range, no. It's kind of the opposite with EV drivers.

The Y has a battery that is 75 kwh compared to the 88 or 91 in the Mach e. So the Y did 2.26 mi/kWh at 16F and the Mach E did 1.93 mi/kWh. Correct, a 38% loss of each. In the summer, Y did 3.63 mi/kWh where the Mach E did 3.11.

Sure: the math is clear - the Model Y is more efficient with its electricity usage. That's the tradeoff for being ugly. But the market has spoken, at least for now, efficiency is not what it cares about -- it cares about range, and the Tesla heat pump doesn't give it an advantage in real world testing.

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