Average miles/kWh over a full year - Less than I expected

[the golden eel]

I did some math back in October, but was thinking about it today and thought you folks would be interested.

From October 2023 thru September 2024, my Emporia app says I used a total of 6630 kWh.

Oct - 561 kWh
Nov - 627
Dec - 615
Jan - 721
Feb - 644
Mar - 781
Apr - 553
May - 436
Jun - 386
Jul - 383
Aug - 428
Sept - 495

I've never charged anywhere else other than home, so these kWh are the only kWh that went into my car for those 12 months.

During those 12 months, I drove 16,500 miles.

16,500 miles divided by 6630 kWh is 2.5 m/kWh.

90% of our driving is city streets and suburban roads - very rare that it is taken on the freeway at 70+ mph. Also, this was with the stock Michelin tires that came with the car.

This was definitely lower than I expected, as I normally see 3.5-4.5 m/kWh on the car's display for a good 6-7 months a year, and then 2-2.5 m/kWh for a few months in the winter. On the below zero days it is under 2 m/kWh, but there aren’t many of those days over the course of a year, and I’m generally not out running around more than necessary when it's that cold.

I would have bet I was above 3.0 m/kWh.

To be clear - 2.5 m/kWh is my car's efficiency calculated from the all the power that I pay for, taken from the wall. Not my efficiency from the car's extended range battery.

I'm guessing charging losses are a fair amount more than what most of us expect. But I would say a big hit to my yearly average is that I precondition the battery 5-6 times a week for a good 4 months a year in the winter.

This isn't a complaint. Just sharing some real-world numbers.

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[Mach-Lee]

That’s about 84 MPGe, which is probably close to what your window sticker says.

Efficiency from the wall will always be less than efficiency from the battery due to charging losses.

 

[the golden eel]

That’s about 84 MPGe, which is probably close to what your window sticker says.

Efficiency from the wall will always be less than efficiency from the battery due to charging losses.

I just looked at the window sticker. Says 91 MPGe - 97 city and 84 highway. I'm guessing that MPGe number is from the pack, and not the wall.

My buddy drives a Tesla, and he had told me his charging loss is around 10%. So I would think we are all that or more.

My daily driving scenario is pretty ideal for EV efficiency - other than that I live in Minnesota. I'm guessing all the preconditioning drags me down a fair bit as well.

 

[Teslaeata]

Last time I looked at the spreadsheet at 41mths & 100,000 miles my average was 2.88m/kWh from the wall so would be slightly better if I used charge power at the car.

I thought that was fairly good given a lot of my mileage is 70mph (ish) with heaters & A/con nearly always on, plenty of early dark morning starts and late dark night finishes.

 

[TimK]

Yeah, I bet the MN winter months only get 2m/kWh, driving down your average.
Also, when I compare the charging sessions in my Fordpass vs my electricity provider app,
it's about a 5% difference. Last night I charged 51kWh from the wall, and battery energy added was 48kWh.

 

[Teslaeata]

That’s about 84 MPGe, which is probably close to what your window sticker says.

Efficiency from the wall will always be less than efficiency from the battery due to charging losses.

That’s really interesting!

Never thought to do an analysis of the difference.

Was only ever really interested in what I actually pay for the charge power which is from the wall not to the car when claiming back the cost of charge power which can be attributed to business mileage.

Home charges differ by an average of 7% whilst DCFC by less than 2%.

 

[Herbknowsit]

Pretty much what my numbers show as well Mr. Eel us being Great Lakes neighbors. Winter does kill the milage but like you, my driving and home charging is well suited for EV's.
When I see figures quoted like 84MPGe it doesn't quite equate in my feeble brain. I won't go into the math but after 10 months of ownership I wanted to know what my savings in "fuel" would be over my former 30 mpg ICE vehicles over the same distance. In summer my savings was 60% with the MME and in winter 47%. I erred on the low side but going in with the purchase, I figured I'd be happy spending half as much on juice versus gas and I'm doing better than that. Of course the MME is waaay more fun to drive.

 

[Teslaeata]

At 109,196 miles my stats show a saving of £7,881.85 over an ICE doing 40mpg at UK fuel prices.

Used total of 38,347.64kWh costing £10,679.77.

580 home charges cost £4,755.73 for 28,967kWh
322 DCFC charges cost £5,924.04 for 9,380.11kWh

 

[Herbknowsit]

Nice savings Teslaeata. I did my math at $3.19 per gallon of gas which I know is really low compared to many areas. Here in the US the gas weasels keep prices low enough to make it seem like EV's are a bad bet. But many of us expect at some point gasoline prices will have to rise and rise again. Just wait until the next refinery calamity or weather extreme situation.

 

[Teslaeata]

Nice savings Teslaeata. I did my math at $3.19 per gallon of gas which I know is really low compared to many areas. Here in the US the gas weasels keep prices low enough to make it seem like EV's are a bad bet. But many of us expect at some point gasoline prices will have to rise and rise again. Just wait until the next refinery calamity or weather extreme situation.

We’re about 8 of your US Dollars per gallon at the minute and that’s quite low for now!

 

[Mach-Lee]

I just looked at the window sticker. Says 91 MPGe - 97 city and 84 highway. I'm guessing that MPGe number is from the pack, and not the wall.

My buddy drives a Tesla, and he had told me his charging loss is around 10%. So I would think we are all that or more.

My daily driving scenario is pretty ideal for EV efficiency - other than that I live in Minnesota. I'm guessing all the preconditioning drags me down a fair bit as well.

MPGe is from the wall, so you are getting the rated highway efficiency of your vehicle.

 

[devmach-e]

Your November through March kWh numbers are significantly higher than the rest of the warmer months of April through October. I can make an educated guess as to why those numbers are higher: your preconditioning. My guess is there’s an extra 1000 kWh consumed by that over the course of the last year. If you redo the math based on 5630 kWh, you get 2.93 miles per kWh. And after factoring in ~10% charging losses, it actually boosts you up to 3.25 miles per kWh from the battery.

 

[Murse-In-Airy]

This is why I only precondition if I truly need a warm battery to provide extra range for a long drive. I’m rarely driving over 50 miles a day. So I rarely need to precondition. With short drives, preconditioning seems to be throwing money away. There is the argument that preconditioning may extend the life of the battery, but the cars haven’t been around long enough to have a cost/benefit analysis on that.

 

[gcagora]

This is why I only precondition if I truly need a warm battery to provide extra range for a long drive. I’m rarely driving over 50 miles a day. So I rarely need to precondition. With short drives, preconditioning seems to be throwing money away. There is the argument that preconditioning may extend the life of the battery, but the cars haven’t been around long enough to have a cost/benefit analysis on that.

I’ve been thinking about this, too. I have a very short commute….rarely over 10 miles in a normal weekday. I’m trying to figure out battery life in the winter vs. wasted kWh.

 

[ChehRob]

Petroleum broadly is priced globally, excluding local taxes. Hence the worldwide EV transition is going to reduce gasoline demand. At the same time there are a lot of countries that depend largely on FF production to fund the economy. This dynamic will work to keep gas competitive. Some producers can ramp up and ramp down depending upon prices, particularly US producers. Pricing is complex.

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