2.2 M/kWh - Can anyone "beat" that?

[planet4ever]

No, I haven't been racing, flying on the freeway, climbing hills, or even gunning it at stoplights. For the past six days I've just been making a few short trips in town.

10.1 miles total, and 4 bars gone.

2.2 m/kWh is probably roughly comparable to our Prius getting 20 mpg. Now, I know that can happen in a Gen 2 Prius like ours if you make very short trips spaced far apart. Gasoline engines are incredibly inefficient when they are cold, and Toyota's Hybrid Synergy Drive doesn't seem to be able to escape that. But I didn't expect an electric motor to be grossly inefficient when it was cold.

Let me make this clear -- I'm not talking really cold weather, like below freezing. Our nighttime low temperatures here have been around 40°, and I've only been driving the car in the afternoon and early evening when the outside temperatures are probably around 55° to 65°. I've also been making trips so short that there was no point in turning on the heater. I am talking about battery temperatures between 4 bars and 5 bars (perhaps because I park outside), but I'm not even sure why the battery temperature would affect the dash m/kWh. Headlights? Sure, but only low beams.

The areas in town where I have been driving are essentially level, +/- 30 feet. I have probably gone up to 4 acceleration bubbles occasionally, but I haven't done any braking beyond very gentle. I started with an 80% charge, and I have not seen more than one unavailable regen bubble during the whole time. So what is going on?

Ray

 

[GeekEV]

That seems WAY low. I'd have the dealer look at it. You may have a bad battery!

 

[EVDRIVER]

I've had 2.1. Unless it is consistent over a long time I would not be worried.

 

[gbarry42]

The dash gauge seems to be an average, which includes a past history of 0.0 when you start out. On my commute, it starts way low and climbs, same way the Prius would when it included its 20MPG warmup in the average.

For the heater, you say you didn't need it, but does that mean you didn't use it? As in, you look at the energy gauge and it isn't drawing 1500W to warm up. Sometimes mine is on and I don't realize it.

Finally, the bars, which looks kinda worrisome. Does down 4 bars mean you have 8 now, or 6? I often overlook the fact that I start with 10 and not 12. If I really want to know the story, I would plug it into the Blink and go back to 80%, then read the KWH that it used to recharge it.

I know it looks bad, but it's probably some kind of illusion. I have had similar experiences but never obsessed about it. Maybe we should look into this. I like telling folks that a short trip doesn't waste energy like a cold ICE car would. I hope that doesn't turn out to be wrong.

 

[GeekEV]

I've had 2.1. Unless it is consistent over a long time I would not be worried.

Wow. Maybe you guys reset more often than I do. I pretty much drive it like I stole it and my long term average is 3.5...

 

[planet4ever]

The dash gauge seems to be an average, which includes a past history of 0.0 when you start out. On my commute, it starts way low and climbs

Yes, I have always been suspicious of that. Even when the temperature was ideal it seemed that m/kWh rarely started out higher than 3.0 after I reset it. But that is one time only after reset, and I reset it only after charging. I'm talking here about one reset, then six days of short trips. I don't know how many, but I'd guess 10-15 times that I powered the car up.

For the heater, you say you didn't need it, but does that mean you didn't use it? As in, you look at the energy gauge and it isn't drawing 1500W to warm up. Sometimes mine is on and I don't realize it.

I know what you mean, but I am quite conscious of that. I usually switch immediately to the energy usage screen unless my wife is with me and wants to use the radio. That hasn't happened much, if at all, on these very short trips. I think the climate control system has been off the whole time this last week. No, wait, there have been a couple of times that I turned on the rear window defroster because the inside of that window was fogged up.

Finally, the bars, which looks kinda worrisome. Does down 4 bars mean you have 8 now, or 6? I often overlook the fact that I start with 10 and not 12. If I really want to know the story, I would plug it into the Blink and go back to 80%, then read the KWH that it used to recharge it.

I had dropped from 10 bars to 6. No Blink available to me; I charge using Phil's EVSE upgrade. I could have charged back to 80% tonight at 120v, which would have allowed me to use my KillAWatt meter, but in fact I am charging to 100% because I'll be doing quite a bit of driving tomorrow. (I normally don't even charge until I get down to 5 bars.)

Ray

 

[TangoKilo]

13,500 miles so far and my lifetime average is 4.3 m/kwh... 2.0 seems awfully low. Did you check your right shoe for lead?

 

[rmerte]

One more possibility - when you first start at 100% charge, there is no regeneration. So my average is worse for short trips when starting at a full charge, compared to an 80%. You should be able to check carwings to see how much regen was received during those miles.

 

[Caracalover]

It takes a lot of energy to move any car. Stop and go or several short trips is going to kill any efficency, so the number is likely accurate. Take it out for a longer drive and you will see the number go up quickly.

The electric car is still better than any other choice at this time, since you didn't wear on the starter, pistons, etc. etc.

80% charge is not really 10 bars, or so I have heard. It is really like 9.7, so you may have only used a little over two - those bars are not all that accurate, and cycling the car on and off often gives a worst case scenario.

 

[SanDust]

For short trips in winter 400 wh/mile would not be crazy in cold weather but 55F is not all that cold. I'd also suggest not worrying about it unless it persists or you can confirm the numbers. Rather than looking at the car meter you can read the draw from the charger and approximate the usage. That would eliminate one variable.

Or take it on a longer trip and see what happens. My guess is that it's an reading anomaly.

 

[GaslessInSeattle]

my lifetime average is 4.2. My worst average over several weeks was 3.3 but that was before I figured out how to really turn off the Climate control and defog without it. recently I've been hovering between 4.2 and 4.0 with extensive preheating and timed charging close to when I use the vehicle to keep the battery warm.

 

[TonyWilliams]

my lifetime average is 4.2. My worst average over several weeks was 3.3

My worst for a tankful was 2.9 in heavy rain with the heater going.

Of course, I can get less than 2.9 within the top bar or two, since regen is limited.

 

[gbarry42]

The OP was talking about the efficiency over a few days' driving. Not his lifetime. This discussion was intended to look at the effects of short trips.

As for measuring charge energy, you can approximate it by time. In your particular case, you have to "learn" how long it takes to go from 80 to 100 percent using your EVSE, so you can subtract that out. The blink takes about 90 minutes to do this bit.

 

[planet4ever]

One more possibility - when you first start at 100% charge, there is no regeneration. So my average is worse for short trips when starting at a full charge, compared to an 80%. You should be able to check carwings to see how much regen was received during those miles.

No, as I stated, I had only charged to 80%. I don't do carwings. It shows 0 miles traveled since one time last October when my wife "accidentally" pushed the OK button.

For short trips in winter 400 wh/mile would not be crazy in cold weather but 55F is not all that cold. I'd also suggest not worrying about it unless it persists or you can confirm the numbers. Rather than looking at the car meter you can read the draw from the charger and approximate the usage. That would eliminate one variable.

By the "charger" do you mean the charging dock/EVSE? I don't have any way to get numbers from that, as I use Phil's EVSE upgrade. I considered a TED, but it won't work with my full breaker box and rather unusual electrical configuration.

Or take it on a longer trip and see what happens. My guess is that it's an reading anomaly.

As I said in my last post, I charged to 100% last night because I knew I'd be driving quite a bit today. This morning I traveled 56.1 miles. I dropped to one bar at about 51, got LBW at 53.0, and I suspect I was 2 or 3 miles from VLBW when I pulled into my driveway, because the GoM was flashing 5. So it's certainly a good thing I charged to 100%.

The better news was that I was at 3.4 m/kWh for the trip. This was mostly freeway, mostly 61-62 mph, and with the heater on most of the time. Last summer I would have expected something around 40.0-4.1 for a trip like that, but I can live with 3.4. I need to travel another 25-30 miles this afternoon, so the car is charging at the moment. It's very unusual for me to charge in the middle of the day, but at least my TOU electric rate is off-peak until 5 PM in the winter.

Ray

 

[evnow]

One way to get bad m/kwh is to run the heater while the car is parked (like in the parking lot of grocery store when one person goes to get some stuff and others are in the car).

 

[surfingslovak]

This morning I traveled 56.1 miles... The better news was that I was at 3.4 m/kWh for the trip.

Thank you for sharing this data, Ray, and I'm sorry to hear about the energy economy numbers you are getting lately. My lowest MPK figure was 2.6 or 2.8. This was most likely due to speeding on the freeway. Anyway, the trip distance of 56.1 miles and 3.4 m/kWh imply 16.5 kWh out of the battery. That would be OK for an 80% charge, but not for a 100% charge. That's rather curious data point.

 

[Caracalover]

This morning I traveled 56.1 miles... The better news was that I was at 3.4 m/kWh for the trip.

Thank you for sharing this data, Ray, and I'm sorry to hear about the energy economy numbers you are getting lately. My lowest MPK figure was 2.6 or 2.8. This was most likely due to speeding on the freeway. Anyway, the trip distance of 56.1 miles and 3.4 m/kWh imply 16.5 kWh out of the battery. That would be OK for an 80% charge, but not for a 100% charge. That's rather curious data point.

Heater on pulling 3-4 KW for an hour of driving brings that up to 20 out of the battery, so about right.

 

[surfingslovak]

Heater on pulling 3-4 KW for an hour of driving brings that up to 20 out of the battery, so about right.

Hmm, I don't know. Perhaps. But it might make some sense if Ray ran the heater when the vehicle was not moving. That would then imply 16.5 kWh for motive energy and perhaps 3 or 4 kWh for heating when the Leaf was stopped.

 

[mark13]

The worst I have ever had was 5.3 KW/M Ray next time you drive the Leaf look out the back window and see if there is a trailer following you :lol:

I wish i could drive your car to see if there is something wrong with it..I have noticed that cold weather will rob your mileage also..I wonder if there could be a brake issue ,maybe a stuck emergency brake..

 

[N1ghtrider]

The worst I have ever had was 5.3 KW/M Ray next time you drive the Leaf look out the back window and see if there is a trailer following you :lol:

I wish i could drive your car to see if there is something wrong with it..I have noticed that cold weather will rob your mileage also..I wonder if there could be a brake issue ,maybe a stuck emergency brake..

You mean 5.3 M/KWh of course.