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Nissan Leaf gets 99 MPG with no gas tank
Giving a vehicle that uses no gas a MPG rating is less confusing?

EVs are big news today and there are two high-profile vehicles that use electricity coming to the market in the U.S. very soon. The Nissan Leaf is a pure EV with no emissions and no tail pipe. The Chevy Volt is a more confusing animal with a gasoline engine that charges the battery pack in the car when the electric motor can no longer run alone.

The Leaf has been granted its EPA fuel efficiency label and that's where things get confusing. The EPA was looking for a way to allow consumers to compare EVs to traditional vehicles that use the miles per gallon rating so they concocted a formula that applies a MPG rating to vehicles like the Leaf that use no gasoline.

The EPA figures that 33.7 kilowatt hours of electricity is equal to a gallon of gasoline and bases their formula off that number. The official EPA number for the Leaf is 99 miles to a gallon. That number is reached by combining the 106 MPG rating in city driving with the 92 MPG on the highway rating. That is impressive and may be perfect for some drivers. However, many drivers will be concerned about the low driving range for the vehicle. Nissan has long touted that the Leaf will go for 100 miles on a single charge. The EPA put the Leaf through five different tests to simulate different driving situations to arrive at its driving range.

The EPA pegs the Leaf for 73 miles on a fully charged battery. Many factors could change that driving distance though from temperature to how much the AC and other accessories are used. To confuse things even more, on the window of the Leaf the FTC will have a sticker that displays the driving range of the car at 96 to 110 miles on a full charge. 

That means that the Leaf will wear stickers that show an EPA rating for 99 MPG despite the fact it has no fuel, an FTC sticker showing 96 to 110 miles per charge, Nissan's long-touted 100-mile driving range, and the EPA 73 miles per charge number. Oddly, all of these stickers claim the common goal of making it easier for EV shoppers to tell how they equate to other EVs and traditional vehicles as well as hybrids. The EPA figures the Leaf will cost about $561 in electricity yearly.

"We're pleased the label clearly demonstrates the Nissan LEAF to be a best-in-class option, reflecting that it's a pure electric vehicle, uses no gas, has no tailpipe and has zero emissions," said Scott Becker, senior vice president, Finance and Administration, Nissan Americas. "The label provides consumers with a tool to compare alternative-fuel vehicles to those with a traditional internal combustion engine and allows them to make an informed purchase decision."



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RE: And...
By Hiawa23 on 11/23/2010 12:50:34 PM , Rating: 2
I know I am missing something here, but the whole electricty vs gas argument is interesting. So, it doesn't use gas but aren't you trading one evil for another, I mean it costs to make electricity, or is the idea solely to reduce foreign oil dependancy, or look like we are. I am curious, can you make these green vehicles look alittle more sportier, cause this one reminds me of the design for the Prius? The Volt atleast looks appealing. Looks like the only segment that will be buying these out of the gates are the rich, too. Seems useless to compare it to fuel based vehicles mpg scale, but I guess they have to sell the vehicle.


RE: And...
By CharonPDX on 11/23/2010 2:00:20 PM , Rating: 2
Basically all studies have shown that an EV, even if 100% of the electricity used to charge it comes from coal, is still cleaner per mile (in terms of both CO2 output and soot pollutants) than even a hybrid.

What we really need is a "miles per KWh" or similar. Show the ENERGY used, not a goofy comparison to gasoline. That would also be a 100% accurate assessment for electric, plug-in hybrid, conventional hybrid, or any other alternative fuel, as well as gasoline.

Here's a good PDF showing costs per efficiencies: http://avt.inel.gov/pdf/fsev/costs.pdf


RE: And...
By MrTeal on 11/23/2010 2:36:54 PM , Rating: 4
That's basically what this is trying to do. Since 1 gallon of gasoline contains 115,400BTU (121MJ, 33.7kWh), they're saying that 1 gallon of gas can be used interchangeably with 33.7kWh of electricity. You can convert to get the miles per kWh if you'd like.

I agree with you though, it's a silly way to do it. They should just say it gets 3 mi/kWh. I was unable to find if the number they use for electricity consumed is the energy from the batteries, or the energy entering the charger and taking into account charging losses.


RE: And...
By Sharpie on 11/23/2010 4:30:27 PM , Rating: 5
quote:
They should just say it gets 3 mi/kWh


Problem is most people are not smart enough to understand what that means and to compare it to what they are familiar with.


RE: And...
By wavetrex on 11/24/2010 2:13:17 AM , Rating: 1
quote:
They should just say it gets 3 mi/kWh

My electric scooter gets about 45 mi/kWh. Cars are horribly inefficient.
If I stuff it with good-enough quality LiFePO4 batteries it could easily go 200 miles/charge. There is a downside however, it doesn't go very fast...

And it's air conditioning is free! :)


RE: And...
By Rasterman on 11/24/2010 12:17:16 PM , Rating: 3
I'm surprised they used this conversion as it doesn't really tell you the true MPG. ICE are only 30-40% efficient, where power plant to wheels in an all electric are 80-90% efficient, meaning even though 1 gallon of gas has 121MJ, an ICE car will only be able to use 40-60MJ of it, where an electric car will be able to use 100MJ of it. So the 99MPG number should be multiplied by 2 at least making it 180MPG.

Another metric is cost, use the average national price per KWH, calculate how much it costs to drive 1 mile in energy, use the 5 year average cost of gas to determine your MPG, this actually make the most sense to me since that is what consumers should care about. How much they are giving to Saudi Arabia every year in fuel dollars.

24kWh battery * $0.10/kWh = $2.40 to fill up the car to drive 100 miles, works out to 2.4 cents per mile

a 20MPG car would take $9 in gas to go 100 miles, or 9/cents per mile, 3.75X the cost

so the yearly cost in fuel at 12,000 miles
20MPG car $1080
leaf $288

over 10 years
$10,800
$2,880

That is $8,000 that is going directly into your pocket instead of sending it to OPEC and mainly Saudi Arabia, multiply that by a million people or so and suddenly it is easy to see why the government helping us to drive more fuel efficient cards is such a good idea for not only the environment, but the also economy.


RE: And...
By Mint on 11/27/2010 9:37:35 AM , Rating: 2
Efficiency of energy use is not very useful for the consumer. Actual cost is.

Assuming that Mr Teal is right about how they calculated the 33.7 kWh = 1 gal gas figure, we have ourselves a nice coincidence: 33.7 kWh @ $0.10/kWh = $3.37, or roughly the cost of one gallon of gasoline.

So the EPA rating makes sense for the consumer.

If 3 miles per kWh was equated to 180 MPG, then that would mean you could get 60 kWh of electricity for the cost of 1 gallon of gas. That is not the case for the vast majority of Americans.


RE: And...
By mindless1 on 11/23/2010 10:56:20 PM , Rating: 2
That's not entirely accurate.

http://blogs.edmunds.com/greencaradvisor/2010/08/o...

I propose that we do not need mi/KWh but rather cost/mile that includes the additional selling price of the EV over an equivalent ICE vehicle (in size) and the cost of a 2nd battery pack since ICE vehicles tend to last longer than one battery pack would.

There's no such thing as a 100% accurate assessment though, especially when you consider that repair costs for the first few generations of hybrids will tend to be highest of any type, then the first generation of an EV till all design quirks are worked out, then ICE vehicles.

What I am really wondering is if it costs less to drive the EV once you make the investment to buy it, might it simply result in people driving more miles since they aren't paying per mile but rather the initial expense of the car itself is wasted if they don't?

Right now I schedule and combine trips when I go out in my ICE to not waste as much gas, but if the cost per mile goes down a lot then I'd make more trips out.


RE: And...
By goku on 11/24/2010 3:02:52 AM , Rating: 3
quote:
Basically all studies have shown that an EV, even if 100% of the electricity used to charge it comes from coal, is still cleaner per mile (in terms of both CO2 output and soot pollutants) than even a hybrid.

Prove it.. Most data I've seen actually states that a Prius is cleaner than most electric vehicles if the electric vehicle is charged primarily by coal. Otherwise they're in dead heat for most of the time due to the mix of coal and other power sources, and then doing better than the Prius when charged with renewables and or natural gas. This 99mpg of the leaf is useless when it comes to figuring out CO2 emissions. You can't just take the aggregate power production of the U.S and figure out your emission from there, you really have to figure out where you're getting your power from in order to have any sort of realistic comparison.

If you're charging your car in northern california, Washington or in Texas, the electric car is for you if you care about CO2 emissions, otherwise in other states like Ohio, you'd be better off with a Prius.


RE: And...
By Keeir on 11/24/2010 5:03:30 PM , Rating: 2
Hello goku,

The problem with most studies is that the tend to make questionable assumptions.

For example, some will argue "99 MPG" is not acceptable for comparison to a Prius like hybrid because we don't know the efficiency/type of the power supply, while ignoring that the Prius's "50 MPG" claim ignores the real cost of refining and transporting the gasoline!

There are many ways to look at the situation. But looking forward into the future, the Leaf is a first swing at an electric car, whereas the Prius is the 4th generation Hybrid. If we see similar improvements in technology in successive car generations, it won't be long until the Electric is the better choice everywhere. (It is already the clearly better choice if your local power mix is more than 30% Nuclear/Hydro/Renewable or less than 60% Coal)


RE: And...
By monkeyman1140 on 11/24/2010 10:52:46 AM , Rating: 2
If we had just gone metric in the 1980s we wouldn't be scared of KwH, Newtons, Joules, etc...


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