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The official Electric Car discussion thread

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tweakmonkey said:
My friends have a Fiat 500e and don't get this.

I tell them when it's cold wear a sweater. Don't run the climate control. Granted this is CA.

Also they never use the heated seats and I think they're probably a lot more useful for heating up a body and extending range vs the climate control which is blowing heat everywhere. I love my heated seats 🙂
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It's really emphasized on my Prius Plugin. On a moderately cold day like today (-10C), I can run the car on EV, but it's cold in the car. The car has no engine noise because the ICE is completely off.

However, if I turn on the heat, suddenly the ICE comes on. Essentially, the purpose of the ICE isn't to power the wheels, but it is to heat the cabin. However, since the ICE will produce more energy than is necessary, it partially powers the wheels too and also charges the EV battery. Unfortunately, if I then shut off the heater, the ICE still often stays on for a couple of minutes, I guess because of the software algorithms they have chosen to use. I guess they figured if the engine needs to come on, they may as well keep it on for a little while.

However, I often leave my heated seats off. I personally am not a huge fan of heated seats, and heated front seats don't help the rear passengers (my kids in child car seats) at all. Heated car seats don't heat up my feet either, or my hands. I have a wrapped steering wheel, but I don't have a heated steering wheel. Yes I wear gloves, but if it's cold enough in the car where my hands still feel cold with gloves on, then it's too cold for my kids in the back.
 
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JCH13 said:
Vdubchaos - you to cite some sources for the inane claims you're making. Nothing you're saying is ringing true.
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I would guess that he heard ICEs are most efficient at WOT, because there are minimal pumping losses at that point. The trouble is, of course, that there are a myriad of other frictional losses that an electric motor does not need to overcome, and is just pulling misinformation from his ass.
 
natto fire said:
I would guess that he heard ICEs are most efficient at WOT, because there are minimal pumping losses at that point. The trouble is, of course, that there are a myriad of other frictional losses that an electric motor does not need to overcome, and is just pulling misinformation from his ass.
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I would guess the same thing.

Not that it has much to do with EVs, but there is an interesting article on the specific fuel economy of various modes of transportation for people and cargo:

http://en.wikipedia.org/wiki/Energy_efficiency_in_transportation

It's worth noting that EVs are around 80-90% efficient with their electric energy. If they are charged with fossil fuel power plants, which are 33-60% efficient, they are at least as efficient as ICE vehicles, up to ~twice as efficient. The rule of thumb I learned when I was studying this is that a good EV sedan of modest size gets the equivalent of 120MPG, in terms of total energy consumption. See: http://en.wikipedia.org/wiki/Miles_per_gallon_gasoline_equivalent
 
It also depends upon the locale of the EV, in terms of CO2 emissions.

There is a lot of coal burning in the US for power, and in fact, coal is the number one source of power in the US (at about 40%), but it varies greatly from state to state. Interestingly, I'm told that Toyota never released the Prius Plug-in in the dirtiest states.

In Canada, on average the CO2 emissions for an EV car are roughly 1/3rd of the US average, but in places like Quebec, the CO2 emissions are less than 1/50th of the US average, since 97% of Quebec power is hydroelectric. In Ontario most of the power is nuclear and hydro, with some natural gas. As far as I know, there is no coal at all used for power generation anymore in Ontario. (It was <3% coal back in 2012.)

What does mean in terms of numbers?

In North America, the average CO2 output is something like 170-225 g/km for an ICE.

In the US the average is something like 135-200 g/km for an EV.
In Canada the average is something like 50-75 g/km for an EV.
In Ontario it is something like 45-70 g/km for an EV.
In Quebec it is something like 2-3 g/km (!) for an EV.
 
Eug said:
It also depends upon the locale of the EV, in terms of CO2 emissions.

There is a lot of coal burning in the US for power, and in fact, coal is the number one source of power in the US (at about 40%), but it varies greatly from state to state. Interestingly, I'm told that Toyota never released the Prius Plug-in in the dirtiest states.

In Canada, on average the CO2 emissions for an EV car are roughly 1/3rd of the US average, but in places like Quebec, the CO2 emissions are less than 1/50th of the US average, since 97% of Quebec power is hydroelectric. In Ontario most of the power is nuclear and hydro, with some natural gas. As far as I know, there is no coal at all used for power generation anymore in Ontario. (It was <3% coal back in 2012.)

What does mean in terms of numbers?

In North America, the average CO2 output is something like 170-225 g/km for an ICE.

In the US the average is something like 135-200 g/km for an EV.
In Canada the average is something like 50-75 g/km for an EV.
In Ontario it is something like 45-70 g/km for an EV.
In Quebec it is something like 2-3 g/km (!) for an EV.
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This!

EVs are as efficient, or not, as the electricity they are charged with. They are better than ICEs, but how much they are better can vary greatly.
 
JCH13 said:
Please do! But no time to sit through a youtube video right now...
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In a nutshell, it take 4.5 to 6 kWh of electricity (almost always coal-generated) to make a gallon of gasoline. Most lower-MPG cars are already using more electricity than EVs. Driving electric takes a whole step and ingredient out of the mix- instead of using electricity and oil to drive, you drive on just electricity.

Edit: this article goes in depth on the issue, and it's more complicated and difficult to give a kWh/gal number- results vary. Apart from electricity, though, the proposal of considering all effects, beyond the immediate emissions, is still rougher on ICE cars than EVs.
 
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Eug said:
FleetCarma-Electric-vs-Gas-Fuel-Efficiency-below-freezing3.png
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I call bullshit on that chart. ICE mileage doesn't go down by 20% in the winter. And the problem isn't just the efficiency, it's the range. Even using their vastly overstated 20% difference (and likely understated EV losses, as they're a biased organization) An ICE can afford to lose range, they can already go hundreds of miles on a fill up. Most EVs right now have a tiny range, so losing 20% of that range means you don't get to work and back.
 
BoberFett said:
I call bullshit on that chart. ICE mileage doesn't go down by 20% in the winter. And the problem isn't just the efficiency, it's the range. Even using their vastly overstated 20% difference (and likely understated EV losses, as they're a biased organization) An ICE can afford to lose range, they can already go hundreds of miles on a fill up. Most EVs right now have a tiny range, so losing 20% of that range means you don't get to work and back.
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I lose 20% on my ICE in the winter. 18MPG summer to 14.3MPG winter. I have a 14.5gal tank and I do not get hundreds of miles per tank. Light comes on at 4 gals left so that's 150 range before fill-up in the winter. Max assuming I got every drop out of the tank would be 207 mile range in the winter (not that I would ever do that).

Even my last car I got a 20% drop in winter. 28MPG to 22MPG.
 
cbrsurfr said:
I lose 20% on my ICE in the winter. 18MPG summer to 14.3MPG winter. I have a 14.5gal tank and I do not get hundreds of miles per tank. Light comes on at 4 gals left so that's 150 range before fill-up in the winter. Max assuming I got every drop out of the tank would be 207 mile range in the winter (not that I would ever do that).

Even my last car I got a 20% drop in winter. 28MPG to 22MPG.
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I've gotta agree on that one, I get ~27 in the summer and ~20-22 in the winter. The chart numbers aren't totally insane.
 
nedfunnell said:
In a nutshell, it take 4.5 to 6 kWh of electricity (almost always coal-generated) to make a gallon of gasoline. Most lower-MPG cars are already using more electricity than EVs. Driving electric takes a whole step and ingredient out of the mix- instead of using electricity and oil to drive, you drive on just electricity.

Edit: this article goes in depth on the issue, and it's more complicated and difficult to give a kWh/gal number- results vary. Apart from electricity, though, the proposal of considering all effects, beyond the immediate emissions, is still rougher on ICE cars than EVs.
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To play devil's advocate a bit, are there numbers on how much fuel is burned to construct a substation or HV transmission line? It is probably a large number, but if you factor in how much energy said lines/stations will transport over their lifetime, still makes the case for electrons. Petrol fuel is very energy dense, but if you have a dedicated network to transport energy 24/7 that is almost impervious to snarls which impede transportation of petroleum, again, electrons look pretty good.

Another question I have is about stoichiometry. Does the colder, denser air of winter affect fuel economy as well, or is it just the higher ethanol blend in winter fuel which contributes to the increase in consumption? The last time I was tweaking cars, I remember most O2 sensors were very inaccurate at knowing true AFR, and took a while before they would be in closed loop mode. I know they have heaters know to alleviate the latter problem, but are wideband O2 sensors more common now?
 
JCH13 said:
I've gotta agree on that one, I get ~27 in the summer and ~20-22 in the winter. The chart numbers aren't totally insane.
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I average around 23.5 year round in an ICE, but I do like 90% of my mile as city miles. I also live in a part of the country where temps fluctuate a great deal.
 
natto fire said:
To play devil's advocate a bit, are there numbers on how much fuel is burned to construct a substation or HV transmission line? It is probably a large number, but if you factor in how much energy said lines/stations will transport over their lifetime, still makes the case for electrons. Petrol fuel is very energy dense, but if you have a dedicated network to transport energy 24/7 that is almost impervious to snarls which impede transportation of petroleum, again, electrons look pretty good.

Another question I have is about stoichiometry. Does the colder, denser air of winter affect fuel economy as well, or is it just the higher ethanol blend in winter fuel which contributes to the increase in consumption? The last time I was tweaking cars, I remember most O2 sensors were very inaccurate at knowing true AFR, and took a while before they would be in closed loop mode. I know they have heaters know to alleviate the latter problem, but are wideband O2 sensors more common now?
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Cold air does a few things:

-More aerodynamic resistance because the air in denser and more viscous
-Colder tires (and winter tires) have a higher rolling resistance
-Some components operate less efficiently in the cold

Colder air does improve the power output of the engine at a given throttle position, but only because more air, and thus more fuel, is consumed. This does not improve fuel economy as it is more than offset by the deleterious effects above and the other effects outlined in the chart Eug posted.
 
My buddy just got an invite from Honda to extend his 3-year lease on his Fit EV for another 2 years, with a price reduction to $199 a month. Incredible. $50 a week, how can you say no? I've seen the Leaf for $199 a month on lease, but the Fit EV has unlimited miles, maintenance, and collision coverage included. Awesome!

http://www.autoblog.com/2015/03/23/honda-fit-ev-lease-199-month/

http://cleantechnica.com/2015/03/26/honda-fit-ev-leases-extended-hydrogen-fcv-delayed/

He was thinking about an i3, although that was a hefty price hike, but this method saves him $60 a month & gives me a couple extra years out of the deal. Will be interesting to see how the battery holds up over time!
 
https://www.fueleconomy.gov/feg/coldweather.shtml

Fuel economy tests show that, in short-trip city driving, a conventional gasoline car's gas mileage is about 12% lower at 20°F than it would be at 77°F. It can drop as much as 22% for very short trips (3 to 4 miles).

The effect on hybrids is worse. Their fuel economy can drop about 31% to 34% under these conditions.

Note that the graph I posted above has the 19% ICE efficiency drop at 0F (not 20F like in the above study). So, it seems these numbers (from the study and from that graph) are reasonable, as they are roughly in the same ballpark.
 
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I live in North America, in a big city - Toronto. My driving is >90% city, and consists of 10 mile commutes to/from work, and small trips in the 1-20 mile range on weekends and sometimes in the evenings.
 
Eug said:
https://www.fueleconomy.gov/feg/coldweather.shtml

Fuel economy tests show that, in short-trip city driving, a conventional gasoline car's gas mileage is about 12% lower at 20°F than it would be at 77°F. It can drop as much as 22% for very short trips (3 to 4 miles).

The effect on hybrids is worse. Their fuel economy can drop about 31% to 34% under these conditions.

Note that the graph I posted above has the 19% ICE efficiency drop at 0F (not 20F like in the above study). So, it seems these numbers (from the study and from that graph) are reasonable, as they are roughly in the same ballpark.
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That I would believe, the engine doesn't even warm up in 4 miles. Still, it's cherry picking data because the average commute in the US is almost a half hour.
 
BoberFett said:
That I would believe, the engine doesn't even warm up in 4 miles. Still, it's cherry picking data because the average commute in the US is almost a half hour.
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Toyota Echo, 1.5L was kicking out hot air at 1.3 miles from home this morning, when it was 32°.

neutral-youre-the-man.-l.png
 
skyking said:
That first 1.3 miles is the worst. Short commutes will bring down any average, especially in winter.
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I commute 2.5 miles, so I only really get heat for half my commute. I do take longer trips "to town" occasionally throughout the week. The Echo gave me 37mpg last fillup.
 
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