1% battery use per mile

[JohnFoxeSheets]

I would suspect lower temps in darkness as the more significant factor. Including the lack of radiant heat benefit from sunshine through the windows we get during the day. That extra boost helps us need less heating in daylight.

I think you’re in to something Tim. More heat needed at night could definitely reduce efficiency considerably. And the air is denser too.

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[DevSecOps]

I recall that @DevSecOps has similarly reported lowered efficiency driving at night. There was a bunch of discussion about possible causes, though I don't recall headlights as being in the equation. Wind is certainly a possibility, as is air density.

John, you remember correctly. I've documented this phenomenon many times on the forum. Most of the time it's met with naysayers or people trying to analyze my drive from the opposite side of the US. I have tons of data proving that night time driving is less efficient.

In the last 2 years I made 73 trips with the MME from Sacramento to Monterey, on the same day, to and from. It's about 190 miles each way.

I always leave Sacramento at 7am and I always leave to return at 7pm. Based on that info, I always drive there when there's sunlight and I always return in partial or full darkness.

Both locations have the same elevation, so there's no difference in incline/decline in one direction. I've done this same route in winter and in summer. Our summer night temps in the valley are in the 80s and there's definitely no heat running. Traffic is always about the same either way.

Based on my trip data, documented here on the forum and tons of additional data I always got 2.4-2.7 mi/kw in daylight and approximately 1-9-2.1 mi/kw in the dark. I would actually set cruise control about 4mph slower at night because I can't lookout for cops as easy in the dark. Additionally, many times I would only use heat in the morning, during daylight. So even with the decreased speed, and heat in the morning I still had worse efficiency at night.

People can say what they want, but after ~25k miles of same day roundtrip commutes, day vs night, I think I know what the data proves.

 

[JohnFoxeSheets]

From the National Weather Service: Once the sun sets, a thin layer of air in contact with the ground turns colder and denser as the downward heat transfer via conduction gets underway

 

[rhougey]

John, you remember correctly. I've documented this phenomenon many times on the forum. Most of the time it's met with naysayers or people trying to analyze my drive from the opposite side of the US. I have tons of data proving that night time driving is less efficient.

In the last 2 years I made 73 trips with the MME from Sacramento to Monterey, on the same day, to and from. It's about 190 miles each way.

I always leave Sacramento at 7am and I always leave to return at 7pm. Based on that info, I always drive there when there's sunlight and I always return in partial or full darkness.

Both locations have the same elevation, so there's no difference in incline/decline in one direction. I've done this same route in winter and in summer. Our summer night temps in the valley are in the 80s and there's definitely no heat running. Traffic is always about the same either way.

Based on my trip data, documented here on the forum and tons of additional data I always got 2.4-2.7 mi/kw in daylight and approximately 1-9-2.1 mi/kw in the dark. I would actually set cruise control about 4mph slower at night because I can't lookout for cops as easy in the dark. Additionally, many times I would only use heat in the morning, during daylight. So even with the decreased speed, and heat in the morning I still had worse efficiency at night.

People can say what they want, but after ~25k miles of same day roundtrip commutes, day vs night, I think I know what the data proves.

Todd, I certainly am familiar with many of your posts, but haven't run across this subject before. However, your experience mimics mine on this subject. I'm glad for some validation of my experience. I was skeptical myself of the phenomenon for a good while.

In my case, I have made 85-90 round trips in the Mach-E over the last 2-1/2 years between the bay area and Lakehead, north of Redding, a distance of 235 miles each way. There is an elevation gain of approximately 1250 ft going north, and the corresponding loss going south. The prevailing wind is usually coming out of the north, but sometimes is blowing in the reverse.

Range experiences between the trip north and the trip south are obviously different, so I do not try to compare range going north to range going south. The constant is that trips in either direction use measurably more energy in the dark than in the light after calculating for temperature and wind speed. Whatever the cause, it is undeniable to me, and I do have to take the darkness into account when driving north at night when it's cold or windy. I never use the cabin heat when making the north trip (unless my wife is in the car) because I don't like to have to stop in Anderson.

 

[Mach1E]

John, you remember correctly. I've documented this phenomenon many times on the forum. Most of the time it's met with naysayers or people trying to analyze my drive from the opposite side of the US. I have tons of data proving that night time driving is less efficient.

In the last 2 years I made 73 trips with the MME from Sacramento to Monterey, on the same day, to and from. It's about 190 miles each way.

I always leave Sacramento at 7am and I always leave to return at 7pm. Based on that info, I always drive there when there's sunlight and I always return in partial or full darkness.

Both locations have the same elevation, so there's no difference in incline/decline in one direction. I've done this same route in winter and in summer. Our summer night temps in the valley are in the 80s and there's definitely no heat running. Traffic is always about the same either way.

Based on my trip data, documented here on the forum and tons of additional data I always got 2.4-2.7 mi/kw in daylight and approximately 1-9-2.1 mi/kw in the dark. I would actually set cruise control about 4mph slower at night because I can't lookout for cops as easy in the dark. Additionally, many times I would only use heat in the morning, during daylight. So even with the decreased speed, and heat in the morning I still had worse efficiency at night.

People can say what they want, but after ~25k miles of same day roundtrip commutes, day vs night, I think I know what the data proves.

I think this proves without a doubt that the sun is warm. ?

Only kind of kidding, but I would expect solar radiation to heat your car and the black road more in the daylight, even if the exterior temps are identical.

Headlights as mentioned shouldn’t make a measurable difference.

Not sure what else it could be, unless the area you are driving has more wind at night time.

 

[Benny’66]

32F.
Heater on.
Pre conditioned battery to 100%
First 80 miles of journey (reasnobly flat 65-70mph highway) used 37% so not too bad. Return leg the remaining battery was ticking down with the miles. 30% remaining at 30 miles but 25% remaining at 26 miles.... Holy crapballs batman.... screen showed 2.5 mi/kWh but it was more than 1 for 1.
Turned off heating and remaining % went down half as fast. Cabin was absolutely freezing, seat heaters don't warm your feet or face.
Ended up using 85% of battery for 160 miles, in the summer exact same trip is ~70%.
Not impressed in the cold.

Just to clarify one point you mentioned. “Pre conditioned battery to 100%” I assume means you set your departure time and had your Mach E plugged in the whole time? Was this the case when you started your return? Because if not, on your return the car needed to rewarm the batteries using internal power.

 

[DaMeatMan]

32F.
Heater on.
Pre conditioned battery to 100%
First 80 miles of journey (reasnobly flat 65-70mph highway) used 37% so not too bad. Return leg the remaining battery was ticking down with the miles. 30% remaining at 30 miles but 25% remaining at 26 miles.... Holy crapballs batman.... screen showed 2.5 mi/kWh but it was more than 1 for 1.
Turned off heating and remaining % went down half as fast. Cabin was absolutely freezing, seat heaters don't warm your feet or face.
Ended up using 85% of battery for 160 miles, in the summer exact same trip is ~70%.
Not impressed in the cold.

What temperature do you have the cabin heating set to? The Mach-E will pull 5k - 7kw for heating, so if your driving around in freezing temps with your jacket off, and your cabin is cooking with summer temps of 73f - 77f on the inside, I hate to tell you your doing the whole EV driving in the winter thing wrong my friend.

I precondition with departure time in the morning, i keep cabin heat set at 65f on auto (level 1), i wear my jacket, and I have seat heat on low, and I'm toasty warm and comfortable, windows are always defogged and this morning it was 23f outside and I got an average consumption of 2.7 miles per kwhr driving an average of 70 miles per hour on the highway for my 1 hour long morning commute of 60 miles. I also charge to 90% daily, and my GOM routinely tells me I have an estimated 248 miles. That estimate is ussually accurate to within 10 to 15 miles of actual usable range in the real world based on my observations.

 

[Neandrewthal]

Was your return trip at night?
It seems nobody mentions it, but in my experience on a long trip, the range loss with the headlights on is definitely noticeable. I do the same 235 mile trip repeatedly always at 75mph, and can almost perfectly predict my SOC at my destination, by checking windspeed & direction, elevation change, and ambient temperature beforehand. When the only other variable is headlights, it is apparent. I only use the heated seats or heated steering wheel when outside ambient temps get into the mid 40's or below, and then only for a couple minutes at a time.

I can assure you, the headlights don't meaningfully impact range. Rough energy usage:

Headlights: 0.1 kW
heated seats: 0.1 kW
heater: 6kW
maintaining 70mph: 25kW

 

[dbsb3233]

i keep cabin heat set at 65f on auto (level 1), i wear my jacket, and I have seat heat on low, and I'm toasty warm and comfortable

If I kept the temp at 65F, I sure wouldn't be toasty warm. Everyone is different for the temperature they like, of course, but that's chilly for us. 71-72F is our comfortable norm. Heated seats on 1 and steering wheel heater on. A warm butt and fingers isn't enough for our tastes. We want the cabin comfortable for nose and feet and everything else. If we couldn't keep our $60k car at a comfortable temp, we'd get rid of it and buy something that can handle it.

It's like when the government tells us we should set the furnace at 68F in the winter and the air conditioning at 78F in the summer, my response is "Are you &#*$ing crazy?!?". ?

 

[DevSecOps]

I think this proves without a doubt that the sun is warm. ?

Only kind of kidding, but I would expect solar radiation to heat your car and the black road more in the daylight, even if the exterior temps are identical.

Headlights as mentioned shouldn’t make a measurable difference.

Not sure what else it could be, unless the area you are driving has more wind at night time.

I don't know why it happens, but it's not the heat or cabin climate. Yesterday I wrote my post when I got home from doing the same roundtrip drive.

When I left home in the morning my battery temp in my R1T was 75 and the outside temp was 32. When I returned my battery temp was 101 and outside was 48. Winds were calm at 2mph from the east mostly which should have no impact.

John might be right with density of the air. I'm not claiming it has to do with just headlights, but something happens at night to cause less efficient driving. My R1T is much less impacted than my MME was, but nonetheless it still happens. I'll look at the same data driving my M3P when I pick it up Thursday.

 

[dbsb3233]

I don't know why it happens, but it's not the heat or cabin climate. Yesterday I wrote my post when I got home from doing the same roundtrip drive.

When I left home in the morning my battery temp in my R1T was 75 and the outside temp was 32. When I returned my battery temp was 101 and outside was 48. Winds were calm at 2mph from the east mostly which should have no impact.

John might be right with density of the air. I'm not claiming it has to do with just headlights, but something happens at night to cause less efficient driving. My R1T is much less impacted than my MME was, but nonetheless it still happens. I'll look at the same data driving my M3P when I pick it up Thursday.

Someone with an MME seeing worse efficiency in the dark could get an extra clue by checking the trip meter detail screen to see which of the 4 battery usage categories seems to be taking the hit.

 

[bigredx86]

Listen, I read nothing as I just saw this thread and this immediately popped into my head.

Please remove your foot from the floor, the gas pedal needs to come up for air once in a while, lol.

That is all, please carry on.

 

[DevSecOps]

Someone with an MME seeing worse efficiency in the dark could get an extra clue by checking the trip meter detail screen to see which of the 4 battery usage categories seems to be taking the hit.

I've looked at it. Unfortunately I think it's not at all accurate. Either way I've had the opposite results from what I would expect. When I first noticed this it was a week into my ownership. I originally attributed it to increased passenger weight. I ruled that out quickly as I noticed the same thing happening with just me in the car.

 

[DaMeatMan]

If I kept the temp at 65F, I sure wouldn't be toasty warm. Everyone is different for the temperature they like, of course, but that's chilly for us. 71-72F is our comfortable norm. Heated seats on 1 and steering wheel heater on. A warm butt and fingers isn't enough for our tastes. We want the cabin comfortable for nose and feet and everything else. If we couldn't keep our $60k car at a comfortable temp, we'd get rid of it and buy something that can handle it.

It's like when the government tells us we should set the furnace at 68F in the winter and the air conditioning at 78F in the summer, my response is "Are you &#*$ing crazy?!?". ?

It sounds to me like an EV (any EV), might not be a good fit for you personally, particularly with your desired winter usage, and you may want to look into a more traditional vehicle.

This has nothing to do with the Mach-E itself, and everything to do with the reality of current battery technology, as well as how heat is created in an EV.

In a traditional internal combustion engine vehicle, the combustion results in a tremendous amount of energy (which is normally wasted) as hot air that is vented out into the atmosphere via the radiator in order to keep the engine within optimal operating temperature. In the winter you are simply redirecting some of that wasted heat into the cabin, rather than venting it off into the atmosphere, so you don't take a hit on range, since your not using additional gasoline to create the heat for the cabin... it was being created anyway as waste heat.

In an EV however the drive train components are way more efficient, and you are not already creating a bunch of waste heat via normal driving that can otherwise be scavenged and redirected into the cabin to keep you warm. As a result you need to fire up a 5000w - 7000w PTC heater (which draws 5 to 7 times more power than a home space heater) just to heat the cabin in the vehicle. Obviously that's a TREMENDOUS amount of power that you are now using to heat the cabin, that is no longer available to propel your vehicle forward. It is for this reason that EV drivers (should know) that in order to achieve "normal" summer like range, you need to limit (as much as possible) any wasted energy consumption that goes into anything other than moving your forward.

There are other methods of heating an EV such as component heat scavenging, as well as the use of heat pumps (instead of PTC heaters) that are more efficient than the Mach-E heating strategy (and Tesla probably does this best), but the bottom line is that you cannot escape the fact that (any EV), will take a hit in range in the winter as the result of demand to heat the cabin, and the battery.

With all of that said, we have not even touched on the fact that the physical battery chemistry itself becomes less efficient, and less energy dense with colder weather. So all other things being equal, even with zero energy used to heat the battery or the cabin, you still have less available energy capacity on board to drive you forward when the battery is cold. A large majority of this range loss can however be mitigated through the use of battery preconditioning via a departure time which heats the battery using grid power, rather than onboard battery power prior to leaving for your daily commute. The battery itself will stay warm for hours due to the sheer mass of the battery.

 

[dbsb3233]

It sounds to me like an EV (any EV), might not be a good fit for you personally, particularly with your desired winter usage, and you may want to look into a more traditional vehicle.

This has nothing to do with the Mach-E itself, and everything to do with the reality of current battery technology, as well as how heat is created in an EV.

Oh just the opposite. I think you misunderstood. We drive the hell out of our Mach-E on road trips (35k miles so far just on long road trips). It's a great fit for us, for many reasons. Including because it CAN handle setting heat to a comfortable 71-72F. That's where I think you misunderstood. I wasn't saying it couldn't, I was saying IF it couldn't, then I'd buy something else that could. But it can. At least for the way we drive long distance. We do a lot of 2000-4000 mile trips, including in the winter where it might be 20F instead of 80F. And I plan our trips carefully to charge up to 80% and leave a lot of safety buffer for most charging stops. I don't like the EV purist approach of showing up at <10% where cold or headwind or detours have us praying we'll make it.

Anyway, the point is Mach-E can handle it for our wants/needs. If it couldn't, we'd get something else (or just drive our Bronco Sport on most road trips instead).

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