I pay SCE $0.21/kWh for my power. Does the car give any info that I can use to calculate cost per mile with this info?
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Approximate cost per mile?
- Thread starter Kimmi
- Start date
With a 100kW hour battery that is 100x$0.21 or $21 for a full charge. If you drive 210 miles then that is $21/210 or $0.10 per mile.
Your car is less, probably 70kW usable. And your range is higher, maybe 300 miles, but you get the idea.
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Yes, it tells you how many watt-hours per mile you're getting (Wh/mile). Unfortunately, I don't think Tesla takes into account charging losses (most automakers don't) as charging isn't 100% efficient. Not all the energy coming out of the "wall" makes it into the battery and even some of that is lost as waste heat.
Someone else will need to comment about vampire losses and energy use from certain features (e.g. sentry mode).
The generally accepted number is around 254 wh/mile, so you'll go almost exactly 4 miles on 1000 wh(aka 1kwh), or ($0.21/4) per mile travelled
I'm sure someone is gonna chime in that their lifetime average is 194.57 wh/mile running 180psi in the tires (kidding... don't try that!) and never using the heat/ac and going 45 mph tops, never using sentry or anything, but Tesla itself uses ~254.
It might be a bit above 254 in real life. I haven't looked recently, but I vaguely recall seeing my 37k miles are at a lifetime average of 270 or somesuch, and with no effort whatsoever toward saving energy. There's also some wastage for Sentry or battery conditioning. The latter probably isn't an issue in California.
The wh/mile numbers are available on the various odometers(Trip a, Trip B, since last charge, and since start of trip(I think that's one, anyway)) It seems to be general practice to rename one of the Trip's to 'Lifetime-do not reset', and just let it chill forever. I didn't do mine until ~500 miles.. oh well.
I vaguely recall there's also a running-wh-average reported on the 'consumption' screen as well.
I'm sure someone is gonna chime in that their lifetime average is 194.57 wh/mile running 180psi in the tires (kidding... don't try that!) and never using the heat/ac and going 45 mph tops, never using sentry or anything, but Tesla itself uses ~254.
It might be a bit above 254 in real life. I haven't looked recently, but I vaguely recall seeing my 37k miles are at a lifetime average of 270 or somesuch, and with no effort whatsoever toward saving energy. There's also some wastage for Sentry or battery conditioning. The latter probably isn't an issue in California.
The wh/mile numbers are available on the various odometers(Trip a, Trip B, since last charge, and since start of trip(I think that's one, anyway)) It seems to be general practice to rename one of the Trip's to 'Lifetime-do not reset', and just let it chill forever. I didn't do mine until ~500 miles.. oh well.
I vaguely recall there's also a running-wh-average reported on the 'consumption' screen as well.
Just for fun, I thought I'd redo the math on my 2008 Saab 9-3's cost-per-mile, given today's gas/electric prices(approx)
26mpg combined, on super unleaded
2.60 per super unleaded gallon.
$0.10 per mile, just in gas.
Local electricity prices are $0.26 per kwh, leading to a $0.065 price per mile on the 3.
And of course, I haven't had to do any regular maintenance on my 3 yet. That will add at least another penny per mile to the Saab's operating costs, but at the same time I bet there's a penny per mile of vampire losses on the 3.
26mpg combined, on super unleaded
2.60 per super unleaded gallon.
$0.10 per mile, just in gas.
Local electricity prices are $0.26 per kwh, leading to a $0.065 price per mile on the 3.
And of course, I haven't had to do any regular maintenance on my 3 yet. That will add at least another penny per mile to the Saab's operating costs, but at the same time I bet there's a penny per mile of vampire losses on the 3.
If you really want to zoom in on your car's actual electricity costs, you can use a third party app like "Stats."
Stats will give you daily, weekly, monthly, yearly cost breakdown, based on the actual charging data from your car. Love it.
Stats will give you daily, weekly, monthly, yearly cost breakdown, based on the actual charging data from your car. Love it.
AlanSubie4Life
Efficiency Obsessed Member
Use that lifetime meter mentioned, in the car. Since you are in Southern California, a decent rule of thumb for typical situations is to multiply that number by 1.25, (add 25%) to account for charging and vampire losses.
If you use Sentry a lot, or you drive just 5k miles a year or something, you’ll need to use an even higher multiplier.
In cold environments, 1.4 or 1.5 is a better choice.
Then take the result converted to kWh/mi, and multiply it by your energy rate (kWh/mi * $/kWh = $/mi).
For you it will be around 6-7 cents/mi.
Does the charging loss vary if you're using Level 1 or Level 2 chargers? I'm using a trial of TeslaFi and it reports 80% efficiency in charging, but I'm only using a Level 1 charger at home.
Uncle Paul
Well-Known Member
Most SCE plans do not have a single price for all electricity used. They either have a time of use, with higher pricing in the afternoons and lower at night, or tiered systems where the first tranch of power is pretty cheap, but goes up as you use more.
Clever owners will tend to charge up when the costs are lowest. (Usually overnight)
Our home has 3 power sources. We use propane for heat/dryer/cooking, Solar to offset high peak electric costs and SCE to provide continous power from their massive grid. Natural gas is the least expensive of all, but we do not have access to the pipeline.
I use a small inverter generator in case power goes out. Can plug in furnace, router, tv etc to keep things comfortatble in case grid goes down.
While some consider only the economic side of energy, I also tend to get some positive vibes from our Solar system as reducing my footprint on the community.
Clever owners will tend to charge up when the costs are lowest. (Usually overnight)
Our home has 3 power sources. We use propane for heat/dryer/cooking, Solar to offset high peak electric costs and SCE to provide continous power from their massive grid. Natural gas is the least expensive of all, but we do not have access to the pipeline.
I use a small inverter generator in case power goes out. Can plug in furnace, router, tv etc to keep things comfortatble in case grid goes down.
While some consider only the economic side of energy, I also tend to get some positive vibes from our Solar system as reducing my footprint on the community.
Uncle Paul
Well-Known Member
240v is more efficient than 120V. Charges much faster and more efficiently.
With so many variables, it is often challenging to determing the precise cost per mile. Like with an ICE, shorter trips use more fuel than long steady cruises. Cold weather uses more than a warmed up car, etc. An ICE will turn on an automatic choke when cold. Uses lots more fuel than steady cruising. Same with battery. If your car needs to warm up it's battery, it will use more juice than if already warm.
With so many variables, it is often challenging to determing the precise cost per mile. Like with an ICE, shorter trips use more fuel than long steady cruises. Cold weather uses more than a warmed up car, etc. An ICE will turn on an automatic choke when cold. Uses lots more fuel than steady cruising. Same with battery. If your car needs to warm up it's battery, it will use more juice than if already warm.
juliusa
Active Member
About 4 miles per kWh is a good approximation for propulsion, so about $.05 per mile.
Additional energy is consumed for:
- driving fast
- charging losses
- battery heating/cooling
- cabin heating/cooling and pre-heating/pre-cooling
- running electronics when the car is not in use - sentry mode uses a lot
In SoCal my guess is you will end up somewhere around $.07
Additional energy is consumed for:
- driving fast
- charging losses
- battery heating/cooling
- cabin heating/cooling and pre-heating/pre-cooling
- running electronics when the car is not in use - sentry mode uses a lot
In SoCal my guess is you will end up somewhere around $.07
ucmndd
Well-Known Member
Yes, because there is an energy baseline needed to run the car’s computers, charging circuitry losses (AC->DC conversion), and possibly heat the battery if it’s cold enough. That’s generally accepted to be somewhere around 300 watts if the battery heater isn’t running - which is about 20% of the power available on a level 1 charger at 1.44kw.
If you can add energy faster, that 300 watts is a much smaller share of the overall power budget, so you charge more efficiently (although you can start to incur other losses at high amperages - mostly resistance/heat related).
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AlanSubie4Life
Efficiency Obsessed Member
Yes. Probably better to use a multiplier of 1.35 or 1.4 if using 120V/12A (15A) charging. As explained just above.
The best charging efficiency you can get is something like 92%. There’s a plot of actual data and also a theoretical model around somewhere. I linked to it recently. In Tesla’s EPA testing Tesla’s setup gets 88% efficiency, so that is what the EPA MPGe numbers are based on.
Worth mentioning here that the MPGe and efficiency numbers on fueleconomy.gov are AC numbers, but they do not account for vampire and feature drain and cold weather use (preheat primarily), so they represent a definite lower bound (upper bound for MPGe).
And of course the trip meter lifetime meter only counts energy use when not in park, so that extra use is rolled into the 1.25-1.5 fudge factor.
Regarding TeslaFi, make sure you fully understand and dig into what it is doing to arrive at its numbers. It is pretty sophisticated, but it can have errors due to missing data points, and there are even some user-defined scalars that affect the reporting of some numbers (I don’t think that scalar applies to the charging info but not sure). So just use some caution there. It’ll probably be fine, but you need to validate the data before using it.
For the guy/gal that wants an easier setup experience, I gotta give the nod to Stats. While I have had a few buggy issues with Stats, the developer is quick to both answer questions and crunch bugs.
I know that Stats does have a few issues with accuracy in reporting certain things, but if you’re looking for a pretty accurate accounting of total expenses and cost per mile, it does a decent job.
I also like how you can input numbers for an ICE vehicle to compare how much it would’ve cost to drive it vs the Tesla.
One thing people should be aware of, though: the majority of these stat trackers require your Tesla login credentials. If you’re not comfortable giving that info out to a third party, you’ll need to look into other solutions. The ones I’ve heard about that don’t require giving your credentials out have a rather stout learning curve.
Personally, I’ve had zero issues with Stats, and wouldn’t hesitate to recommend it to others.
to calculate cost per mile.
I pay SCE $0.21/kWh for my power.
Since new = 210 miles, 50kWh and 237 W hours per mile as shown on the odometer.
(moderator note: Moved this new thread into your existing thread on the same topic)
I pay SCE $0.21/kWh for my power.
Since new = 210 miles, 50kWh and 237 W hours per mile as shown on the odometer.
(moderator note: Moved this new thread into your existing thread on the same topic)
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Miles per kWh = 210/50 = 4.2 miles/kWh
Price per kWh = $0.21 * 4.2 = $0.882/kWh
50 kWh * $0.882/kWh = $44.10
Price per kWh = $0.21 * 4.2 = $0.882/kWh
50 kWh * $0.882/kWh = $44.10
M3BlueGeorgia
Active Member
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