F56 & U25 efficiency numbers

[teslarati97]

Finally managed to get enough data to get an idea of the winter and mild weather efficiency numbers.

Furry boots (-20F and colder) - F56 @ 1.8-2.0mi/kWh, U25 @ 1.0mi/kWh
Hiking shoes (-19F to 0F) - F56 @ 2.2mi/kWh, U25 @ 1.2mi/kWh
Jandals (1F to 32F) - F56 @ 2.5-2.9mi/kWh, U25 @ 2.0mi/kWh
Gum boots (32F to 50F) - F56 @ 3.5-4.0mi/kWh, U25 @ 2.8-3.2mi/kWh
Bare feet* (51F to 70F) - F56 @ 5.2mi/kWh, U25 @ 4.0 mi/kWh

*The numbers shot up after I switched my wheel & tires for both BEVs. F56 uses summer tires and U25 is all season but I have (lighter) aftermarket wheels for the summer set. I would say it's all a combination of wheel/tires, climate controls, heat pump, and brake regen.

 

[insightman]

Finally managed to get enough data to get an idea of the winter and mild weather efficiency numbers.

Furry boots (-20F and colder) - F56 @ 1.8-2.0mi/kWh, U25 @ 1.0mi/kWh
Hiking shoes (-19F to 0F) - F56 @ 2.2mi/kWh, U25 @ 1.2mi/kWh
Jandals (1F to 32F) - F56 @ 2.5-2.9mi/kWh, U25 @ 2.0mi/kWh
Gum boots (32F to 50F) - F56 @ 3.5-4.0mi/kWh, U25 @ 2.8-3.2mi/kWh
Bare feet* (51F to 70F) - F56 @ 5.2mi/kWh, U25 @ 4.0 mi/kWh

The numbers shot up after I switched my wheel & tires for both BEVs. F56 uses summer tires and U25 is all season but I have (lighter) aftermarket wheels for the summer set. I would say it's all a combination of wheel/tires, climate controls, heat pump, and brake regen.

Loved the categories, waiting for the asterisk.

 

[teslarati97]

Loved the categories, waiting for the asterisk.

Okay, I've added an asterisk at the final part because I did swap out the tires/wheels for the last measurement. I would also add the U25 drives MUCH better once you get rid of the OEM wheels. Winter sets use that HEAVY kaleido spoke vibrant silver wheel set with Continential VikingContact 7 tires, and my A/S set is Replika R266 with Primacy A/S non-runflat.



I would also add I have Thule Aeroblade Edge roof bars that probably takes efficiency down 2-5%. They do whistle faintly at 30MPH & 55MPH so I'll probably add a Thule fairing to the front bar.

 

[MacMini34]

You're a brave man if you're wearing Jandals from 1F to 32F! Check for frostbite on those pinkies

 

[teslarati97]

I mean you can also wear socks with your jandals as post workout footwear in the winter.

Update on the F56, I reached 6.2mi/kWh largely thanks to construction zones and crawling rush hour traffic. I've also put on a wind fairing on the U25 to see if I can get rid of some faint whistling from the roof rack podiums.

 

[SameGuy]

I've been taking a very sedate, residential-streets route to work every day for the past week and a half, driving in Green+ with HVAC off and window(s, and occasionally roof) open, and as a result I'm getting my best efficiency in the almost three years I've owned the F56 Cooper SE.

The Cooper's 28.9 kWh (usable) pack is EPA rated to give 183 km/114 miles of range, as extrapolated from BMW conservatively rating its efficiency at 15.5 kWh/100 km or 4.0 mi/kWh. As of this writing, I've done 201 km (125 miles) on 76% indicated, or 10.9 kWh/100 km (5.7 miles/kWh).

My efficiency has actually gone down a bit as the eastern heat dome settled in. Last week, temps were in the 60s on my morning commute and 70s on the way home, ideal; the last four days, on the other hand, have seen 80s in the morning and upper 90s in the afternoon.

 

[CuriousGeorge]

Somewhat coincidentally, I have been pondering the optimal temperature for maximum efficiency (ignoring the comfort of the passengers). That same heat dome has resulted in an increase in my efficiency, to over 6 mi/kWh even when using the A/C in the afternoons.

 

[teslarati97]

Well it looks like for some the heat dome unlocks the battery buffer by increasing the cell pack voltage. On the side note I am really getting annoyed by the U25 super sensitive tire pressure warnings. The F56 is just so effortless compared to the U25 occasionally finicky UI. Still love both BEVs!

 

[acer54]

Well it looks like for some the heat dome unlocks the battery buffer by increasing the cell pack voltage. On the side note I am really getting annoyed by the U25 super sensitive tire pressure warnings. The F56 is just so effortless compared to the U25 occasionally finicky UI. Still love both BEVs!

My F56 tyre pressure sensors are very sensitive and react to different temperatures and barometric pressures, my previous car (Audi) never gave me any false positives during over 5 years of ownership.

 

[SameGuy]

Somewhat coincidentally, I have been pondering the optimal temperature for maximum efficiency (ignoring the comfort of the passengers). That same heat dome has resulted in an increase in my efficiency, to over 6 mi/kWh even when using the A/C in the afternoons.

I can't possibly drive more slowly or sedately than I've been doing for the past 11 days, I've no clue what else I'd need to do to get from 5.7 to "over 6 mi/kWh." Maybe ignoring stop signs and red lights?

 

[teslarati97]

I can't possibly drive more slowly or sedately than I've been doing for the past 11 days, I've no clue what else I'd need to do to get from 5.7 to "over 6 mi/kWh." Maybe ignoring stop signs and red lights?

Time for an extreme electron binge diet. Turn off the HUD, drive in silence, and no CarPlay. If you are feeling risky you can draft behind a lorry driver, but that's pretty much normal driving in your area. Regrettably, there is no clock screensaver on LCI2.

 

[ghost]

None of that sounds fun.

 

[Puppethead]

Turn off the HUD, drive in silence, and no CarPlay.

Aren't all those powered by the 12 V battery, though? Which leads to the inevitable question: what factors are used to recharge the 12 V battery? Does the SE wait until it gets below a certain percentage before recharging? And is overcharging the AGM battery an issue? What would happen if one were to swap in a 12 V lithium car battery?

I found this article, but it doesn't live up to its headline: 12-Volt Batteries On Electric Cars: Everything You Need To Know

 

[CuriousGeorge]

I've no clue what else I'd need to do to get from 5.7 to "over 6 mi/kWh."

On a good day, I can average over 7 mi/kWh on the way to work, but that's because it is slightly downhill (average -0.2% gradient). The trip home therefore always uses more battery, even if it is cool enough that I don't need to use the A/C.

Flat roads + low speed limits (25-50 mph) + few complete stops (<1/mi) + using less than ~1/2 of max power getting up to speed + limited use of A/C = high efficiency.

 

[teslarati97]

Aren't all those powered by the 12 V battery, though? Which leads to the inevitable question: what factors are used to recharge the 12 V battery? Does the SE wait until it gets below a certain percentage before recharging? And is overcharging the AGM battery an issue? What would happen if one were to swap in a 12 V lithium car battery?

I found this article, but it doesn't live up to its headline: 12-Volt Batteries On Electric Cars: Everything You Need To Know

I think it's around 12.6V (~~80% SoC?) before the DC-DC converter kicks in to take it somewhere around 14.5V?

If you cranked up the HK speakers, let's say it takes 100W of the 360W HK amp...so yeah it's probably going to use the HV battery for recharging the 12V battery.

 

[dyent]

Aren't all those powered by the 12 V battery, though? Which leads to the inevitable question: what factors are used to recharge the 12 V battery? Does the SE wait until it gets below a certain percentage before recharging? And is overcharging the AGM battery an issue? What would happen if one were to swap in a 12 V lithium car battery?

I found this article, but it doesn't live up to its headline: 12-Volt Batteries On Electric Cars: Everything You Need To Know

I have a aftermarket "battery monitoring unit" on my 2023 SE, as soon as car is fired up, voltage goes to 14.5V, so usually that would indicate charge to 12V, just like in an ICE with alternator........
Do not know how much actual drain from high voltage battery to charge or maintain 12V......
David

 

[insightman]

None of that sounds fun.

For 20 years I pretended it was fun to drive slow and get big numbers on my Honda Insight hybrid's Fuel Consumption Display. Living in the slow lane was a tough adjustment after decades of driving various small sports cars. However, my Insight was a gas-guzzler compared to my MINI Cooper SE. My right foot has re-learned what it feels like to press hard on an accelerator pedal. I've never bothered to access my SE's mi/kWh display.

 

[CuriousGeorge]

For 20 years I pretended it was fun to drive slow and get big numbers on my Honda Insight hybrid's Fuel Consumption Display. Living in the slow lane was a tough adjustment after decades of driving various small sports cars. However, my Insight was a gas-guzzler compared to my MINI Cooper SE. My right foot has re-learned what it feels like to press hard on an accelerator pedal. I've never bothered to access my SE's mi/kWh display.

Where I drive, the opportunity to use the SE's ability to accelerate rapidly is almost always limited by the presence of other traffic. Your options are therefore to 1) do what almost everyone else does, which is to accelerate moderately hard, tailgate the car in front of you, then slow rapidly and wait for a couple of minutes at the next light, only to repeat the cycle all over again, or 2) lay back a bit, try to time the lights, and enjoy a smoother ride.

The advantage of approach #2 is that it saves your tires, so that you can put them to use bounding around roundabouts and turning square corners, which is where the real fun is.

 

[Puppethead]

A capability of the SE I like to utilize is taking control of roundabouts. Fortunately for me I have to drive through three or more of them virtually every day.

 

[insightman]

A capability of the SE I like to utilize is taking control of roundabouts. Fortunately for me I have to drive through three or more of them virtually every day.

You're echoing the inspiration for my SE motto (apologies if I post it too often):
"Bounds about roundabouts, quietly acting out."

When was the last time you enjoyed going more than 360° around a roundabout?

I used to look for the paths through town with the least stop signs and stoplights. Now I seek the paths with the most roundabouts. However, there's one large, heavily traveled roundabout I avoid--it annually racks up the most accidents of any intersection in the county.