M3 MR vs Chevy Bolt (energy consumption)

[StealthP3D]

Was this measured at the wall? Your car sounds like a unicorn.

That's also typical for mine when the car is undisturbed in cool weather. The losses actually increase slightly when it's warm due to faster self-discharge.

Most people who are measuring vampire drain from the wall are measuring a lot more than pure "vampire drain". If you open the door to get your purse out the climate control turns on briefly to whatever you have it set at, the computers wake up, the lights come on, etc. In my mind that's not vampire drain but it gets counted as such because people are always waking their cars up whether it's by opening the door, checking it on their app or using third party apps that poll perodically. Some of it is the natural discharge of the lead acid battery, a loss that ICE cars have but never gets measured (except as it impacts their MPG figures).

MPG measurements are crude compared to all the software tools we have to measure electrical losses right down to a small trickle. The reason vampire drain is such a popular topic is because it's so easy to measure with software. With a tank of gas, the most accurate way to measure it is crude in comparison, the pump meter and the odometer. Evaporative losses, battery self-discharge and other "vampire" losses are all rolled into the MPG which is terribly inefficent to begin with so the losses are miniscule in comparison.

 

[scaesare]

Neither of these factors are comparable to the 5% level. Evaporation is a non issue for discussions of factors of this order of magnitude. Gas pump errors will likely average out to zero error (they are calibrated and put under seal). And I would notice both factors with my ICE vehicle. A single gas pump that is miscalibrated matters a lot less than a 5% hit every time you fuel.

Temp alone can make that much of a difference.

And averaging out doesn't matter if the fuel pump close to home you use every week to fill up happens to be the one shortchanging you.

In any case... this is all small enough potatoes that worrying about it for a charge or fill up isn't worth it. It's the range on the road that really matters.

 

[StealthP3D]

And averaging out doesn't matter if the fuel pump close to home you use every week to fill up happens to be the one shortchanging you.

A few years ago the Washington State Department of Weights and Measures, who are responsible for regulating gas pump accuracy, did surprise visits to random gas stations around the state and found a surprising numper of pumps were miscalibrated in the vendors favor between 5-10%. Yes, they had calibration compliance stickers from the private company that certifies accuracy.

Who would have thought that profit motive was reason enough to bypass accuracy regulations? You mean people actually break the law for "free" money? Who would have thunk? Turns out the fines were smaller than the illiciit profits. And no motorists complained because measuring losses in a gas car is pretty imprecise to begin with.

Anyone who tells you ll gas pumps are accurate because they are certified and regulated is living in fantasy land.Try measuring the accuracy of gas pumps in Alabama!

 

[AlanSubie4Life]

Maybe. I’ve never noticed a major discrepancy, and I do pay attention. Remember that you have multiple meters in the car to crosscheck against (gauge, miles remaining, economy since last fill). They have fixed errors but it can all be accounted for. I guess I am in California though - they are pretty good at regulating such things.

Anyway....

Back to the topic - comparing EV efficiency - I wonder if the large efficiency difference is due to the battery architecture? I wonder if the chargers themselves are similar efficiency but there is more heating of the pack in the Tesla?

 

[Daniel in SD]

That's also typical for mine when the car is undisturbed in cool weather. The losses actually increase slightly when it's warm due to faster self-discharge.

Most people who are measuring vampire drain from the wall are measuring a lot more than pure "vampire drain". If you open the door to get your purse out the climate control turns on briefly to whatever you have it set at, the computers wake up, the lights come on, etc. In my mind that's not vampire drain but it gets counted as such because people are always waking their cars up whether it's by opening the door, checking it on their app or using third party apps that poll perodically. Some of it is the natural discharge of the lead acid battery, a loss that ICE cars have but never gets measured (except as it impacts their MPG figures).

MPG measurements are crude compared to all the software tools we have to measure electrical losses right down to a small trickle. The reason vampire drain is such a popular topic is because it's so easy to measure with software. With a tank of gas, the most accurate way to measure it is crude in comparison, the pump meter and the odometer. Evaporative losses, battery self-discharge and other "vampire" losses are all rolled into the MPG which is terribly inefficent to begin with so the losses are miniscule in comparison.

How big do you think the battery is in an ICE vehicle? If there was significant vampire drain the battery would die when you park it for a week.
Evaporative losses came up in another thread and they are very small. There are extremely strict regulations on them.
MPG in ICE vehicles is measured electronically as well, from the fuel injector pulse width.

 

[diamond.g]

How big do you think the battery is in an ICE vehicle? If there was significant vampire drain the battery would die when you park it for a week.
Evaporative losses came up in another thread and they are very small. There are extremely strict regulations on them.
MPG in ICE vehicles is measured electronically as well, from the fuel injector pulse width.

That depends on the vehicle. My Golf TDI's battery only lasted two months (I stopped driving it before giving it back to VW). My dad had a BMW that was constantly killing the battery (he gave the car back, wasn't sure if they ever figured out where the problem was). Infrequent short trips is killing our Subaru forester battery (yay sulfation).

 

[Daniel in SD]

That depends on the vehicle. My Golf TDI's battery only lasted two months (I stopped driving it before giving it back to VW). My dad had a BMW that was constantly killing the battery (he gave the car back, wasn't sure if they ever figured out where the problem was). Infrequent short trips is killing our Subaru forester battery (yay sulfation).

Car batteries are only 50Ah so that's 600Wh. 2 months would be an average drain of 0.83W. Discharging a regular car battery will kill it in short order (that's why Tesla uses AGM batteries). BMWs are crap (Need to hook up a computer to change the battery? Really?). My original 2005 Subaru Legacy battery lasted 7 years.

 

[StealthP3D]

How big do you think the battery is in an ICE vehicle? If there was significant vampire drain the battery would die when you park it for a week.
Evaporative losses came up in another thread and they are very small. There are extremely strict regulations on them.
MPG in ICE vehicles is measured electronically as well, from the fuel injector pulse width.

The ICE vampire drain has to be multipled by the inefficiency of the gas engine, alternator and the charging losses.

Personally, I don't think the vampire drain in my two Model 3's is very significant either, it's less than my cable box/tv (when they're off which is most of the time). In the bigger picture it's pretty insignificant and I can't do anything about reducing it further so it just isn't a priority for me to dwell on it.

I would be more likely to worry about the health of those who dwell on such insignificant things, things that are beyond their control.

 

[AlanSubie4Life]

The ICE vampire drain has to be multipled by the inefficiency of the gas engine, alternator and the charging losses.

Personally, I don't think the vampire drain in my two Model 3's is very significant either, it's less than my cable box/tv (when they're off which is most of the time). In the bigger picture it's pretty insignificant and I can't do anything about reducing it further so it just isn't a priority for me to dwell on it.

I would be more likely to worry about the health of those who dwell on such insignificant things, things that are beyond their control.

In keeping with this thread, if I recall you have separate metering for your garage with your two Model 3s. Would it be possible to post your total metered usage (I know it includes a few other things like lights and such?) vs. your total miles on your Model 3s?

 

[ℬête Noire]

No one is getting 75Wh per day. Where did you get that number? It’s about 1kwh per day in ideal circumstances.

Are you just emptying your mind of things you read that you don't want to exist? Because you've read this.

It's roughly 250Wh, about 10Wh/hr for what appears to be the minimum under optimal conditions & settings.

And I'm not the only one that's seen this.


As to where he got that number, you probably should have followed the link he provided. However in that case it was a flawed measurement because they were plugged in, so it is very probably that the vehicle went through at least one charge cycle somewhere along the line and that number is just where the vehicle happened to be when they returned.

 

[AlanSubie4Life]

Well, I've now turned off data sharing and cabin overheat protection. Can disable the Stats app too (though I won't initially - as it didn't cause me any problems when I started using it). Anything else? Hoping to get this down to the 10W everyone seems to claim is easily achievable. I am hopeful! So much for that Autopilot data for Tesla I guess.

It's roughly 250Wh, about 10Wh/hr

I think Daniel's original complaint was that 75Wh/day is not equal to 250Wh/day, or 1kWh/day (Tesla says 750Wh/day). And the post referenced (which as you say was probably bad data) was actually a ~280Wh/day result. It's worthwhile correcting incorrect information when it is posted. I'm sure it was just a mistake when the 75Wh/day number was posted, but still...

Anyway, getting back to the 28% difference (~60Wh/mi) between the Bolt and Model 3 in this city-driving experiment posted by @Dan123 :

Summary of primary contributors to the difference, as I understand it:

1) Tire grip (probably a bit more rolling resistance & grip for Model 3 - I'd guess 10-15Wh/mi)
2) Vampire drain (about 30Wh/mi in this case - obviously it's going to change depending on how much driving is done)
3) Charging efficiency (about 15Wh/mi in this case - will scale with overall efficiency - so would be larger for a car driven in winter, aggressively, etc.) For the Bolt it is perhaps 7% of the usage (assuming metering in the car can be trusted), while for the Tesla it is 13% of the usage (assuming battery usable capacity is 75kWh).

As mentioned elsewhere, for higher speed runs with more driving per day, the Model 3 will probably substantially close the gap.

Looking forward to an update from @Dan123 with more miles on the Model 3. Not sure anyone else is though.

 

[ℬête Noire]

I think Daniel's original complaint was that 75Wh/day is not equal to 250Wh/day, or 1kWh/day (Tesla says 750Wh/day).

I think Daniel was VERY explicit about what he asserted the minimum was. *checks text* Yup. And by now he should damn well know better. He's not a stupid person in my experience, no idea why he's willfully being the misinformation flip side of 75Wh/day here.

As for the numbers on the linked post, I didn't go through them and recheck. As soon as I saw it had been left plugged in I binned it as not really reliable numbers anyway (as the linked post itself actually noted).

 

[AlanSubie4Life]

I think Daniel was VERY explicit about what the minimum was. *checks text* Yup. And by now he should damn well know better. He's not a stupid person in my experience, no idea why he's willfully being the misinformation flip side of 75Wh/day here.

I am not sure why he quoted the 1kWh/day, either, as the "best in ideal circumstances". With these claims about the data sharing - I'm curious to see how my results change. Certainly without making those changes the "typical" number IS actually close to 1kWh/day (I base that on my experience, Daniel's experience, the experience of a friend at work, and the experience of my brother) - but it perhaps isn't as high as that in "ideal circumstances" - we will see. Obviously the best number is a moving target too, as software updates come and go.

I'll have a new datapoint from my brother in a week or so, too, as he abandoned his car for a couple weeks unplugged. He doesn't have any of the parsimony hacks applied though. No third party app though, so it should be a very clean result. For the record, he left the vehicle at 231 miles (not recently charged) at noon, Friday January 25th. I'm estimating he'll come back to 178 miles on February 8th, if he doesn't have a cold battery indication (this is in Washington state so it will depend on the weather, car is outside in a covered carport).

 

[Daniel in SD]

I think Daniel was VERY explicit about what he asserted the minimum was. *checks text* Yup. And by now he should damn well know better. He's not a stupid person in my experience, no idea why he's willfully being the misinformation flip side of 75Wh/day here.

As for the numbers on the linked post, I didn't go through them and recheck. As soon as I saw it had been left plugged in I binned it as not really reliable numbers anyway (as the linked post itself actually noted).

Yeah I'm very skeptical that anyone is getting 250Wh per day. All the numbers I've heard from people who let their car sit for a significant amount of time is 3-4miles (1 mile = 290Wh according to the Monroney sticker). Your number was from a single day, correct? You have to keep in mind that the measurement of the state of charge of the battery is not very accurate. It can change with temperature so measuring small changes in the miles remaining may not be accurate. I suppose it's possible that your car is special.

 

[ℬête Noire]

Yeah I'm very skeptical that anyone is getting 250Wh per day.

You really need to get over that bit of reality that's bothering you.

All the numbers I've heard from people who let their car sit for a significant amount of time is 3-4miles (1 mile = 290Wh according to the Monroney sticker).

All the people? *cough* Perhaps you mean "all the people I chose not to ignore/dismiss because <no particular reason given>"?

 

[Daniel in SD]

You really need to get over that bit of reality that's bothering you.

All the people? *cough* Perhaps you mean "all the people I chose not to ignore"?

It does bother me that people are getting way less vampire drain than me! Should it not?
That's why I chose to believe that their testing methodology is flawed. Unless they share their secrets with me

 

[StealthP3D]

In keeping with this thread, if I recall you have separate metering for your garage with your two Model 3s. Would it be possible to post your total metered usage (I know it includes a few other things like lights and such?) vs. your total miles on your Model 3s?

I don't know what you can divine from that but since you asked for it:

Model 3 LR: 8,622 miles
Model P3D: 3,086 miles

Total meter usage since installed: 2,436 kWh
At current rates that cost us approximately $270 or about $40/month. These cars are cheap to "fuel". It's cheap enough that we don't hesitate to pre-heat or pre-cool whether it's a long trip or a little trip into town (2 miles).

 

[AlanSubie4Life]

I don't know what you can divine from that but since you asked for it:

Model 3 LR: 8,622 miles
Model P3D: 3,086 miles

Total meter usage since installed: 2,436 kWh
At current rates that cost us approximately $270 or about $40/month. These cars are cheap to "fuel". It's cheap enough that we don't hesitate to pre-heat or pre-cool whether it's a long trip or a little trip into town (2 miles).

Thanks!

It appears nothing can be derived from it. You either haven't had the meter installed from the beginning or you have charged elsewhere. Which is fine, obviously; that's the way things go, only certain people are candidates for easily tracked data.

 

[StealthP3D]

It appears nothing can be derived from it. You either haven't had the meter installed from the beginning or you have charged elsewhere. Which is fine, obviously; that's the way things go, only certain people are candidates for easily tracked data.

Mostly the former. My wife took delivery of her LR in May. The meter didn't get installed until July. But we can tell from our monthly usage there's not enough vampire drain to lose a single minute of sleep over (or spend an inordinate amount of time during the day worrying about it).

 

[Daniel in SD]

Mostly the former. My wife took delivery of her LR in May. The meter didn't get installed until July. But we can tell from our monthly usage there's not enough vampire drain to lose a single minute of sleep over (or spend an inordinate amount of time during the day worrying about it).

And I don't lose any sleep over driving my 17mpg urban assault vehicle because individual actions make virtually no difference to the global environment! However if you add it all up standby power is about 5% of US electricity usage.
If you go by the EPA assumptions and assume 3-4 miles a day of loss the standby power in the Model 3 adds 10% to the energy usage. Now if there's some secret mode that lowers it to 1 mile a day that would be a huge improvement...