EPA range and efficiency of MME

[EVer]

Yep, this will be of much more importance than any published differences in EPA range.

In my Leaf SL+ with a 62 KWH battery, I can get over 280 miles accelerating sensibly in Eco Mode on Secondary roads. If I hammer it down I-90 at 85 mph or so, it will be less than half that.

Agreed, the driver is the biggest variable in range. for any given vehicle.

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[MattG]

Agreed, the driver is the biggest variable in range. for any given vehicle.

I think my wife is going to be happy with this new car...I’m sure I’ll be making a game out of optimizing efficiency on long drives and will be driving a lot less aggressively than our current turbocharged transport! We have a 240 mile route we drive often...no stops currently but it’ll be pushing the limits of the Ford due to terrain and weather.

 

[dbsb3233]

It would be pretty easy, albeit boring, to force that.

The problem is you're getting a bad idea of it. There isn't enough precision in the data, unless you plug into the CANBUS. For example, if you watch you toggle back and forth between the range display and the percent display while charging, you can sometimes see as much as 5 miles of range added before the percent rolls up. Which number will you use for the extrapolation? There are 10-20 miles of uncertainty just due to rounding. And then, you've just looked a one particular case.

A trip planner which looks at actual routes, expected speeds, etc., is a far better tool.

All the more reason NOT to just "Drive the car from 100% SOC to 3-4%". Good chance there's not a charger within a few miles of that point, and the trip planners could easily be wrong by >4%, leaving you stranded. I'd plan for at least a 10% minimum.

 

[dbsb3233]

Agreed, the driver is the biggest variable in range. for any given vehicle.

Variable, yes. But a variable needs a baseline to be applied to, otherwise it doesn't mean anything.
One driver may be 8% more efficient that the average, and another may be 8% less efficient than the average. And over time people will figure out where they fall on the scale. But it doesn't tell us how far we can go on a charge unless we have a baseline average to apply the adjustment to. That's why we care so much about what the projections and route planners say.

 

[ChasingCoral]

Variable, yes. But a variable needs a baseline to be applied to, otherwise it doesn't mean anything.
One driver may be 8% more efficient that the average, and another may be 8% less efficient than the average. And over time people will figure out where they fall on the scale. But it doesn't tell us how far we can go on a charge unless we have a baseline average to apply the adjustment to. That's why we care so much about what the projections and route planners say.

Yes, I really hope Ford does a good job of determining range based on each driver's style as well as current conditions.

 

[EVer]

All the more reason NOT to just "Drive the car from 100% SOC to 3-4%". Good chance there's not a charger within a few miles of that point, and the trip planners could easily be wrong by >4%, leaving you stranded. I'd plan for at least a 10% minimum.

Again, if you want to determine range experimentally, you could easily force it by doing laps local to a charger once you get down to 10%-15%. My thought isn't that you should do one or the other, but rather use planning tools which are aware of the route you will actually be driving. If my destination is the mountains versus the desert, my range and charging stops will be much different. My car tells me predicted SOC along an entire planned route, inclusive of elevation change, expected speeds, etc. It is fundamentally more useful to me than some generic range figure. I'd cite it as the single most important tool in the car. It's unfortunately buried and not integrated with the map, but I presume it is what the navigation system uses to plan charging stops.

Variable, yes. But a variable needs a baseline to be applied to, otherwise it doesn't mean anything.
One driver may be 8% more efficient that the average, and another may be 8% less efficient than the average. And over time people will figure out where they fall on the scale. But it doesn't tell us how far we can go on a charge unless we have a baseline average to apply the adjustment to. That's why we care so much about what the projections and route planners say.

My baseline is lifetime efficiency (mi/kWh or Wh/mi, pick your format). If I average X% less efficient than what the planning tools assume, I can account for it.

Unfortunately to get that in my tesla I have to cordon off one of the trip meters and remember to not clear it (it's called "DON'T DELETE" or something ). Maybe the Mustang will have a dedicated counter.

 

[pb3]

This thread kind of segued into MME vs. Tesla and cold vs. hot weather efficiency vs. range, so I'll dip my oar into the discussion. Disclaimer -- I've only a layman's understanding of the principles and components. I'm using "logic" which may be based on my mistaken assumptions.

Hot weather
- Batteries more likely to be happy operating circa 50 - 90 deg/F
- Battery thermal management basically dumping excess heat into radiators (Tesla heat pump no advantage).
- Both both vehicles use a a compressor to provide cool cabin air.
- Conclusion -- no advantage either way.

Cold weather
- Batteries not as happy under 40 deg/F, high resistance, low efficiency. This affects both driving range and also impacts charge time (slower in cold weather).
- MME, no heat pump, cabin warming from resistive elements, high power budget
- Telsa, heat pump, uses scavenged heat from battery and drive train thermal management *up to a point*. At lower temperatures this heat is used to maintain battery health and is not available for cabin heat which then relies on resistive elements.
- Conclusion -- likely slight/moderate advantage to Telsa

 

[JCHLi]

When it comes to AC (or even heating via the heat pump) it is more efficient to have a larger delta T. Meaning for AC, you want the relatively hot refrigerant exchanging the the relatively cold outside air (not a hot computer or battery pack).

The advantage would be for heat because you are trying to move heat inside, so a heat pump that is tied in to hot components will have a relatively hot component giving heat to the relatively cold refrigerant (bigger delta T then if it tried to find the heat from the air).

 

[dbsb3233]

My thought isn't that you should do one or the other, but rather use planning tools which are aware of the route you will actually be driving.

Oh of course. My reply was about the "Drive the car from 100% SOC to 3-4%" comment. 3-4% is way to risky to plan to IMO, even with the more sophisticated calculators.

My baseline is lifetime efficiency (mi/kWh or Wh/mi, pick your format). If I average X% less efficient than what the planning tools assume, I can account for it.

Yep. That's exactly what I was saying.

 

[SnBGC]

This thread kind of segued into MME vs. Tesla and cold vs. hot weather efficiency vs. range, so I'll dip my oar into the discussion. Disclaimer -- I've only a layman's understanding of the principles and components. I'm using "logic" which may be based on my mistaken assumptions.

Hot weather
- Batteries more likely to be happy operating circa 50 - 90 deg/F
- Battery thermal management basically dumping excess heat into radiators (Tesla heat pump no advantage).
- Both both vehicles use a a compressor to provide cool cabin air.
- Conclusion -- no advantage either way.

Cold weather
- Batteries not as happy under 40 deg/F, high resistance, low efficiency. This affects both driving range and also impacts charge time (slower in cold weather).
- MME, no heat pump, cabin warming from resistive elements, high power budget
- Telsa, heat pump, uses scavenged heat from battery and drive train thermal management *up to a point*. At lower temperatures this heat is used to maintain battery health and is not available for cabin heat which then relies on resistive elements.
- Conclusion -- likely slight/moderate advantage to Telsa

Scavenging heat from the battery and drive train components is not unique to Tesla. The FFE does that so I fully expect the MME to have a similar system.

 

[buzznwood]

Yes, I really hope Ford does a good job of determining range based on each driver's style as well as current conditions.

I think this is where ford wanting to crowd sourced data will help, there is always of course valid privacy concerns that need to be meet first, but the more data to work with the more chance of predicting an accurate range.

Even if you don't want to op in to big brother, I would hope that is has capacity to learn basic routes so if you commute the same way each day it should be able to gain more accurate readings over time.

 

[JCHLi]

A water cooled condenser (I assume it's actual glycol or some other liquid) just adds an extra step of heat transfer, now there is the U factor going from refrigerant to water via one heat exchanger and then another going from water to air via a second heat exchanger. If this is the case it's going to be LESS efficient.

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