Average Miles per Kilowatt (MPK)

[Right123]

Hello FFE drivers, I was wondering what your average MPK is?

 

[Dreaming-in-Focus]

I'm at 4.78 right now in current weather conditions - from battery to wheels.

Hello FFE drivers, I was wondering what your average MPK is?

 

[Arthur]

After about 6 months and 3200 miles, I'm averaging 274 Wh/mi (battery to wheels), which is 3.65 mi/kWh.

 

[nallgaier]

2 months, roughly 1600 miles, averaging about 210 Wh/mi... so 4.76 mi/kWh. Eager to see how that changes during the VT winter!

 

[DavidJohnson]

I'm at 3.65 mi/kWh (274 Wh/mi) lifetime, too. That's 6 months and 2,200 miles.

 

[TedMH]

After 1200 miles I've got 253 wh/mile (3.95 miles per kwH), at least according to the lifetime statistics that display when you turn off the car.

 

[jcjj]

Have almost 6,000 Miles in 7 Months. 3.88 mi/kWh or 258Wh/mi.

Live in San Diego North County where I don't think I can drive for a mile or two without going up or down a hill.

 

[v_traveller]

Just hit 10,000 miles; it's been 7 months. 243 Wh/mi, which is 4.11 mi/kWh.

I was more efficient for the first two months before the HOV stickers got to me. Now, at least a third of the commute is usually at 70+mph to avoid impeding HOV lane traffic. And I'm nearly pegging it at 80-85mph almost daily when I'm entering the lane.

I'm expecting my mi/KWh to take a bit of a dive when the weather cools off. Running that heater really sucks a lot of juice, and the butt warmers just don't do it for me (nothing wrong with the car - I think I might have too much insulation down there).

 

[georgek]

I'm at 241 since Feb 1, 13. And 209 for so far in Sept.

My ford Mobil must be upset, though, because I went from totally zen yesterday, to totally zippy, today :?:

 

[TedMH]

I have a question and a worry. I drive really carefully and it seems to me that I should have a really good average MPK figure. But at best I'm sort of middle of the pack here at 253 wh/mile (3.95 mi/kWh). I never drive over 65MPH and mostly just drive slowly on surface streets trying not to annoy other drivers by going too slow and coasting too soon before a stop.

That said, I get different wh/mile readings depending on where I look. In the car on the left info screen when I turn off the car I see lifetime wh/mile of 253 and I've seen it improve slowly over time as I continue to drive carefully. When I look at the MFM My Driving from my computer I see 241 wh/mile and that number hasn't changed since I got the car. I just figured MFM is completely screwed up on everything else so that number must be bogus. My iPhone MFM app shows consistently better numbers (right now it shows 161 wh/mi (6.2 mi kWh) with 33 kWh consumed so far this month), and I'm pretty sure that's also wrong--I'm careful but I'm not a magician!

Which source are you all using for your average MPK calculations? Do you also show significant variations between sources?

I wish my Kill-O-Watt meter worked with my AV charger so I could get a real calculation of my driving performance... I don't think Ford's are trustworthy.

 

[WattsUp]

I get different wh/mile readings depending on where I look.

Believe the car. As you've noticed, the MFM numbers are crappy "toy" numbers that cannot be relied on.

I wish my Kill-O-Watt meter worked with my AV charger so I could get a real calculation of my driving performance... I don't thing Ford's are trustworthy.

Even if you could measure the electricity coming from the wall used to charge your car, realize that this measurement would also include the charging overhead, and not just the electricity consumed while driving.

Charging a battery is not a 100% efficient energy transfer (if it was, no heat would be generated in the process). The typical EV charging process is more like 80% efficient. In other words, only about 80% of the energy "from the wall" ends up stored in your battery.

For any given charge, you can determine the overhead (overhead = energy from wall - energy stored in battery). But, in general terms, you won't ever know exactly what the charging efficiency is (it varies with the ambient temperature, battery SOC, type of equipment used, etc.). You would have to use an estimate. So, even with a Kill-O-Watt, you still would not have a perfect way to measure Wh/mi.

 

[TedMH]

Hey I just discovered a fourth version of the truth about my driving. The MFM Local rankings (AK, CA, HI, OR, WA) show me in 36th place for the lowest average rate of consumption in Region 1 at 235 Wh/mi!!! That actually seems closer to what I'd guess, given my focus on driving carefully.

It's really silly, this whole MFM thing... too bad.

 

[az erik]

After a weekend I'm getting about 289wh/mile according to MFM, which also claims my 28 miles driven yesterday is actually 2 miles. So it's really hard to say. But the lifetime miles is correct.

Even if you could measure the electricity coming from the wall used to charge your car, realize that this measurement would also include the charging overhead, and not just the electricity consumed while driving.

I don't actually see why the overhead and charger consumption wouldn't be lumped into it. It is after all a cost of running the vehicle. It'd also play a factor in getting an efficient charger. If I could charge my car in 4 hours but it costs me an additional KWh I would want to take that into account.

I'd guess this question has been asked and I should be searching for it but is there a break down of how the L1 vs L2 chargers charge? Say, if an L1 'uses' 2KWh but 'puts' 1.5KWh into the car, vs a L2 that 'uses' 6KWh and puts 5KWh into the car?

 

[WattsUp]

Even if you could measure the electricity coming from the wall used to charge your car, realize that this measurement would also include the charging overhead, and not just the electricity consumed while driving.

I don't actually see why the overhead and charger consumption wouldn't be lumped into it. It is after all a cost of running the vehicle. It'd also play a factor in getting an efficient charger. If I could charge my car in 4 hours but it costs me an additional KWh I would want to take that into account.

Yes, and that kind of thinking is taken into account on the window sticker, where it estimates you'll need 320 Wh/mi to achieve the 76 mile range. That figure is "wall to wheels".

And, yes, while maybe the car "should" somehow lump the total energy into its read-outs, it doesn't. It only shows energy consumed from the battery itself -- "battery to wheels". That is, the "Wh/mi" read-out in the car only indicates how much energy is being consumed from the charge stored in the battery. To achieve the 76 mile range, according to the car, you'll need to keep the energy usage meter around 256 Wh/mi. That's roughly 80% of 320 Wh/mi.

You'll find that 80% ratio everywhere in the energy usage numbers. It reflects that fact that the charging process is overall about 80% efficient, on average. While the battery stores 19.5 kWh of usable energy, you'll find that it takes about 24.3 kWh "from the wall" to charge it to that level. The other energy, about 20%, is simply lost, mainly as heat.

That said, charging efficiency can also vary quite a bit with a bunch of factors, which is probably why the car can't really easily lump it in for you. The best it could do is apply an estimate, whereas it can always measure exactly what was consumed from the battery.

 

[az erik]

That said, charging efficiency can also vary quite a bit with a bunch of factors, which is probably why the car can't really easily lump it in for you. The best it could do is apply an estimate, whereas it can always measure exactly what was consumed from the battery.

Ahh I see. I thought wall to wheels was being ignored, I didn't realize that battery to wheels is actually a unit of measurement in the EV world. I read it as people were ignoring the overhead. Before I bought I used 75% and figured 28kWh per full charge. Looks like I'm gaining a few pennies every time I turn around

 

[WattsUp]

That said, charging efficiency can also vary quite a bit with a bunch of factors, which is probably why the car can't really easily lump it in for you. The best it could do is apply an estimate, whereas it can always measure exactly what was consumed from the battery.

Ahh I see. I thought wall to wheels was being ignored, I didn't realize that battery to wheels is actually a unit of measurement in the EV world. I read it as people were ignoring the overhead. Before I bought I used 75% and figured 28kWh per full charge. Looks like I'm gaining a few pennies every time I turn around

Yes, once the energy has come "on-board" into the battery, most (all?) EVs will only show you how much energy is being consumed from the battery -- "battery to wheels". So, actually yes, "wall to wheels" usage is basically ignored once on-board an EV.

But, the EPA window sticker does not ignore it. The EPA measures the electricity needed "from the wall" to fully charge the EV under test. Then, they drive the car, under their standard conditions, until it stops. They do this several times, take an average, and divide. For the FFE, they came up a typical range of 76 miles and an efficiency of 320 Wh/mi.

Of course, with the right equipment, such as a Kill-O-Watt or something on your wall socket, you can make the same measurements yourself. After all, this is exactly like what you might do with an ICE vehicle... that is, note the gallons "from the pump" and then check your odometer later, in order to track your own personal MPG.

 

[dcast1079]

With 3,800 miles a get the (seemingly) standard 274Kph. I drive in the Zen area and drive from Tracy, CA over the Altamont Pass and of course down the Altamont pass each day.

Side Note... From a full charge (86 miles) I arrive at the top of the Altamont about 12 miles from home with 25 miles surplus but regain almost 40 miles at the bottom. Very scary the first few times. Normal now.

 

[WattsUp]

With 3,800 miles a get the (seemingly) standard 274Kph. I drive in the Zen area and drive from Tracy, CA over the Altamont Pass and of course down the Altamont pass each day.

Side Note... From a full charge (86 miles) I arrive at the top of the Altamont about 12 miles from home with 25 miles surplus but regain almost 40 miles at the bottom. Very scary the first few times. Normal now.

What's 274Kph? You mean 274 Wh/mi?

 

[unplugged]

What's 274Kph? You mean 274 Wh/mi?

That's 274 kilometers per hour. You have no idea how steep that mountain is.