By on November 23, 2010

Why does the Nissan Leaf get a 99 MPG from the EPA? After all, you could pour gallons of gasoline into the thing and it wouldn’t budge an inch. It is, after all, an electric car. But hey, this ain’t America if a consumer can’t glance at a label and say “gosh honey, check out how many em-pee-gees this one gets. That sure is a whole lot of em-pee-gees.” And at least the EPA did include the most important detail: the Leaf’s battery range is rated 73 miles, or about three quarters the range Nissan had been claiming. Of course, as is always the case, your mileage may vary… only the amount of gasoline required by a Nissan Leaf won’t.

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58 Comments on “What’s Wrong With This Picture: The 99 MPG Non Sequitur Edition...”


  • avatar

    Baffling indeed.

  • avatar
    jmo

    It makes sense to me.  I’d think that miles per dollar, based on national average fuel and electricity prices would make a better comparison, but MPGequivalents works as a easy to understand comparison.

  • avatar
    jmo

    Also, what’s with you Niedermeyers and your reflexive, seemingly baseless, anti-EV bias?

    • 0 avatar

      Also, what’s with you Niedermeyer’s and your reflexive, seemingly baseless, anti-EV bias?
      Huh? The only bias here is against meaningless labeling. In general the media has overblown the importance of EVs, but pointing this fact out hardly makes us “anti EV.” In fact, to be perfectly frank, I briefly considered leaping for a Leaf (as my vehicular needs dovetail well with its mission) before deciding that I’ll have the rest of my life to drive an EV. I ended up going with the M Coupe because I wanted to own a fast, distinctive gas-powered car while they’re still around… not because I’m in any way “anti-EV.”

    • 0 avatar
      Paul Niedermeyer

      jmo: would you like to give me one example of my “reflexive seemingly baseless anti-EV bias”?
      For what it’s worth, I think the mpge sticker is fine: it helps put the intrinsic efficiency of EVs in perspective, a useful tool.

    • 0 avatar
      jmo

      The only bias here is against meaningless labeling.

      Maybe I’m mistaken.  But, I’m pretty sure I’ve detected an anti-EV/hybrid bias.  Maybe I’m just reacting to the general luddism of many here on TTAC.

    • 0 avatar
      FleetofWheel

      jmo. Sounds like when someone scoffs that the other side is opposed to change per se but are really just perturbed that their particular proposed change is being met with informed resistance.

      A Luddite would not be on this car-tech site but happily walking somewhere.

    • 0 avatar
      Paul Niedermeyer

      jmo: maybe you were thinking of Bertel Schmitt?

    • 0 avatar
      BDB

      There’s only one person on here how seems to have it out for EVs, but he isn’t Paul or Edward.
      I mean, if you want REAL anti-EV vitriol, head over to Autoextremist!

  • avatar
    dwford

    Can’t wait to see the Volt’s sticker. Probably will need to be a flow chart.

    • 0 avatar
      SkiD666

      The EPA got 99MPGe by using the following formula:
      (33.7 kWh of energy per gallon of gas)/(34 kWh per 100 miles) = 99 MPGe for 73 miles

      Using Insideline’s numbers from their Volt review:
      (33.7)/(39 kWh per 100 miles) = 86 MPGe for 34 miles

    • 0 avatar
      GarbageMotorsCo.

      Um, Government Motors already told us what the mileage was going to be?

      http://gm-volt.com/2009/08/11/chevy-volt-gets-230-mpg-city-epa-rating/

      230MPG

    • 0 avatar
      Robert Schwartz

      What they are doing is equating the thermal energy in a gallon of gasoline (~130 MJ) to an amount of electricity having the same value in Joules where, by definition, 1 KWh is 3.6 MJ.
      The problem with that is that it is far more efficient (upwards of 99%) to convert electricity into motion by use of an electric motor than it is to convert the thermal energy in fossil fuel into motion by the use of any type of heat engine (reciprocating, turbines, etc.).
      The latter process is constrained by the laws of thermodynamics to mundane levels. A modern ICE does well to convert 35% of the thermal energy into motion. Fixed plants, such as those run by electric utilities, can by dint of higher capital investment, increase that level to as much as 60%.
      Of course most electricity is produced by the combustion of fossil fuel and the use of the thermal energy to turn generators. Therefor, ICE will always be at a disadvantage in any comparison that leaves out the original generation of the electricity.
      A fairer comparison would be to haircut the electricity by a factor of 50% or more to reflect that fact. If you do that to the 99 mpg given above, you get 45 mpg. Not so impressive, especially when compared to the Prius and other hybrids.
       

  • avatar
    ash78

    Meaningless. Where’s the Rods-to-Hogshead converter?

  • avatar
    psarhjinian

    Possibly the sticker printing program requires a number and only accepts two digits, so it’s either 99 or 00?

  • avatar
    Educator(of teachers)Dan

    Looking at this sticker in a dealership would simply cause me to utter; “Whiskey, Tango, Foxtrot.”  And walk away shaking my head.

  • avatar
    jaydez

    This makes perfect sense to me.  I used to work for a cell phone store and when someone wanted a pre-paid cell or didnt have an SSn to give we entered it as all 9s.  I 99 just means no data is available!

  • avatar

    so if they’re claiming 99mpg equiv on a 100 mile range, then we’re down to 73 mpg equivs on the 73 mile range, right in Audi A2 territory.
    The e- cost/year is impressive, although I’m sure the lifecycle isn’t so much (what are they selling these things for again, not including the gov’t subsidies?) But then I guess you have to factor in the geopolitical savings.

    • 0 avatar
      Paul Niedermeyer

      David; it doesn’t work that way. The 99 mpge is the efficiency of the Leaf; the range is another matter. You’re mixing oranges and apples.

    • 0 avatar
      protomech

      See SkiD666’s comment above.
       
      “The EPA got 99MPGe by using the following formula:
      (33.7 kWh of energy per gallon of gas)/(34 kWh per 100 miles) = 99 MPGe for 73 miles”
       
      Basically, the EPA measures the energy efficiency of the car on their test cycle, then compares the energy used to energy stored in gasoline.

  • avatar
    dhanson865

    Is this supposed to be a 2011 model?
    It’s not at http://www.fueleconomy.gov/feg/hybrid_sbs.shtml yet but we can compare the stickers 15,000 mile fuel cost (which assumes $2.88 a gallon gas)
    All automatic transmission (best MPG I could find if there was more than one choice for Auto)

    201? Leaf $561
    2011 Prius $864
    2011 Milan/MKZ/Fusion Hybrid $1106
    2011 Cyvic Hybrid $1054
    2011 Insight $1054
    2011 CR-Z $1166
    2011 HS 250h $1236
    2011 Camry Hybrid $1309
    2010 Fit $1395 (2011 isn’t on the list yet)
    2011 Yaris $1395
    2010 Corolla $1490 (2011 isn’t on the list yet)
    2011 Camry 4cyl $1663
    2011 Camry 6cyl $1879

    Did I miss any obvious suspects?

  • avatar

    Paul,

    I’d think it would depend on how they calculate the efficiency. If they are are assuming a certain amount of juice to make the range, but it makes less than that range with the given amount of juice, then the efficiency is proportionally less than they say.

    • 0 avatar
      Paul Niedermeyer

      David; this is the EPA’s measurement, not Nissan’s 100 mile projected range. The sticker says that the range is 73 miles and the mpge is 99. I’m not following your math in trying to rearrange or recalculate the EPA’s number.

  • avatar
    ComfortablyNumb

    Per the EPA’s website:

    “For EV labels, the agencies propose to show electricity consumption in both metrics: as miles per gallon of gasoline-equivalent (MPGe) and as kilowatt-hours per 100 miles.”

    They calculate the equivalent MPG based on specifc energy of each power source – one gallon of gasoline is equivalent to 33.7 kW-hr of electricity (EPA’s conversion factor, not mine).  This makes for a nice simple conversion to dollars spent, which is what consumers will want to know.  It will also give you a direct model comparison, e.g. the Leaf gets 20% higher “MPGs” than the other EV.  What it doesn’t tell you is how much the equivalent in coal or uranium would be, so you can’t compare EV’s to other propulsion systems on the basis of  emissions or environmental impact. Like it or not, this metric provides a good apples-to-apples comparison for EV buyers.  The environmental impact of EVs is a whole other ballgame.

  • avatar
    Dr. Remulac

    ComfortablyNumb touched on it, but here is the total conversion that makes sense to me:

    100 miles / 34 kwhr x 115,000 Btu/gallon gas x 1 kwhr / 3412 btu = 99 miles/gallon gas

    Do the multiplication/division and cancel the units.

    I should add that that this obviously ignores fuel input at the power plant to get the electricity. Power plants vary across the country, but many fossil fuel plants are about 33% efficient. Put another way: 3 units of fuel in, 1 unit of electricity out.

    So one could argue this car is really 33 mpg equivalent.

    • 0 avatar
      jmo

      33%?
       
      More like 60%. So… ~63 mpg?
       
      http://www.ge-energy.com/prod_serv/products/gas_turbines_cc/en/h_system/index.htm

    • 0 avatar
      Dr. Remulac

      I am aware more efficient power plants exist, but as I said, the “grid” average is around 33%. 

      Be aware that even with a optimal 60% efficient plant as you show, that occurs only at ideal conditions, it assumes no transmission losses, and the required spinning reserve which consume fuels while idling.  However, with all the new natural gas finds in this country, I’m sure there is room for improvement for the overall grid, but 60% is far off in the future.

      I am only stating fact and not arguing for or against EV’s.  The fact is that when averaged across the countries electrical grid, this car gets “about” 33 mpge when considering all sources of fuel that go into making our electricity. 

    • 0 avatar
      Steven02

      If you want to talk about sources of fuel, the one also needs to consider the shipping of oil, refining cost energy, and then the shipping of gas to your station.  If you really want to go overboard, you should include the energy used to drill for the oil.  If you do, you should also be counting the cost of mining for coal or uranium or whatever source you are getting for electricity.
       
      But, you should also at that time be complaining that the ICE in your car isn’t 100% efficient in the fuel it is burning to propel the car.  How much of it is lost to heat?

    • 0 avatar
      jmo

      The fact is that when averaged across the countries electrical grid, this car gets “about” 33 mpge when considering all sources of fuel that go into making our electricity

      Do you have site for your 33% efficiency claim for the grid average?

      And, if we’re talking grid average you need to account for the fact that nearly 30% of the power generated in the US comes from nuclear and hydro sources.

    • 0 avatar
      Dr. Remulac

      jmo,

      Check out http://www.eia.gov/ for all the energy data you would want.  Plus I have been working around and in this type of industry for almost 15 years, considering transmission losses, I’ve verbally heard claims between 25 – 35% for the overall grid efficiency  (for fossil fuel plants, you must ignore hydro and nuclear for this calculation).  I have been on plant tours of several local power plants also.  The typical coal plants are about 30-35% eff. at the plant and natural gas are from 30 to 50%.  Those newer, more efficient natural gas plants unfortunately tend to be peaking plants and don’t run 24/7, and only reach 50% during cooler weather.

      Point I’m trying to make is that this particular electric car is no more efficient than most similar sized and hp gas powered car.  It’s only advantage is fuel switching: oil to whatever the grid uses to make the electricity.  So if its global warming your concerned about, I doubt there is a benefit to the Leaf.  If the goal is reducing foriegn oil consumption, then electric cars area a huge benefit….Just don’t pretend one 3,000 lb car is more efficient than the next 3,000 lb car because one’s power plant is elsewhere. 

      And to address Steven 02 of course we could try to account for all the btu’s back to the source and that could seem to go on forever, but it is somewhat equal to consider fuel into a power plant (that also has been mined, refined, and delivered etc…) to mined, refined, and delivered fuel that made it to a car’s gas tank.  Again if we consider all the political and pollution costs of oil then that is the only benefit of this car as far as I see it.

      And no I should not be complaing that the ICE isn’t 100%, that is already included in the stated or actual mpg #’s.  If a Accord for example had 100% eff ICE, then it would get about 100 mpg highway (assuming at 33 mpg it is only 33% eff.).  So the efficiency of a gas engine is directly stated in the mpg figure, whatever it may be.

    • 0 avatar
      Dr. Remulac

      Another and simpler graph that shows the US breakdown of energy consumption and fuel use.

      https://www.llnl.gov/news/newsreleases/2010/images/energy-flow-annotated.pdf

      From here you can see that the grid is estimated at only 32% (12 quads elec. out / 38 quads energy in) including nuclear and hydro.  I am surprised it is this low when including hydro an nuclear.

  • avatar

    so it only holds 3/4 of a gallon?  sheesh, that’s lousy!

  • avatar
    carve

    Where are the kilowatt hours measured: Coming out of the battery, or coming out of your wall (what you actually pay for).  Charging losses should definitely be considered in efficiency.
    I’m just glad there’s a kwh/100 miles rating.  That’s what is really meaningful, since electric costs are so variable.  In fact, they should recalibrate fuel pumps into kwh, too.  That way when they decrease the energy content with ethanol, you can see the price jump.  THAT, rather than mpge, would really give a consistent yard-stick across all fuel sources.

    • 0 avatar
      protomech

      The EPA projects an energy “wallet cost” to be $561 for the typical 15000 miles, or $3.74/100 mi. At their average of $0.12/kwh, that works out to 31 kwh/100 miles at your wallet.

      On the other hand, they calculate range at 73 miles. 24 kwh / 73 miles is 33 kwh/100 mi, though I’ve never seen the Leaf’s allowable depth-of-discharge disclosed. If the 73 mile range is at 90% depth of discharge and recharging is 90% efficient (220v), that gives you around 33 kwh/100 mile at the wall.

      Confusing. They need to document their measurements, assumptions and calculations.

  • avatar
    gslippy

    What I find annoying is that with EVs, journalists (and mfrs) suddenly feel compelled to report the electric motor power in kW, which means nothing to most motorists.
     
    Power can be expressed in HP, kW, Joules, Btu/hr, calories, and so on.  Vehicles have historically been rated in HP.  1 HP = 0.746 kW, so the Leaf’s 80 kW motor = 107 HP.

    • 0 avatar

      and electric motors historically act more like 214 hp when they are 107 hp.

    • 0 avatar
      protomech

      Vehicles have been historically rated in hp in the US, but in kW or sometimes PS elsewhere in the world. Europe, Japan, Australia are all PS or KW.
       
      KW is a more natural rating for electric vehicles, since it relates directly to system voltage, current, and pack capacity. Provided conversions to horsepower are nice for a quick (and somewhat flawed) comparison against gas vehicles, but hp should definitely not be the primary rating for an EV’s output.

  • avatar
    PlentyofCars

    But is that 73 mile range to zero power left, or has the US Government built in a margin of safely??
     
    ie, is 73 three quarters of the range to zero power (about 99 miles).

  • avatar
    GarbageMotorsCo.

    HAHAHAHAHAHA that is pathethic!

    FWIW, the Chevy Volt gets 230MPG!!!! OMG what a POS!

    http://gm-volt.com/2009/08/11/chevy-volt-gets-230-mpg-city-epa-rating/

  • avatar
    Steven02

    This makes me very curious about what rating the Volt will get.  Assuming it gets 99 mpge, what will the range be?  I am pretty shocked that the range for the Leaf got an EPA rating of 73 miles.  I thought it would have been more.

  • avatar
    tparkit

    The only goal of assigning a mileage rating to an EV is so that the car can be included in the CAFE rating.

    The CAFE calculation takes into account the number of vehicles produced, which is where GE’s (a.k.a. “Government Electric”) recent promise to purchase a heap of GM’s Volt comes into play in the service of the Washington/GM/UAW axis.

    http://www.thetruthaboutcars.com/2010/11/good-news-for-korea-gm-will-build-more-volts/

    • 0 avatar
      mike978

      GE is General Electric – when did it change its name. At this rate no company will want a G as an initial because loony people will insert Government in there regardless of facts.
       
      CAFE should be abandoned and a reasonable gas tax should be instituted much like Europe (although not at their levels). This would then leave companies free to sell whatever cars they wanted to and people pay to play. No Aston Martin Cygnet crap.

    • 0 avatar
      tparkit

      Gosh, you’re right, Mike. Here, why don’t you start your reading with the loony people at the Wall Street Journal…

      http://www.downsizinggovernment.org/government-electric

      …and carry on from there browsing wherever your spirit of inquiry carries you…
       
      http://www.google.ca/#hl=en&source=hp&biw=1916&bih=820&q=general+electric+%22government+electric%22&aq=f&aqi=&aql=&oq=&gs_rfai=&fp=7c84e8e55e4f5f
       

  • avatar
    ash78

    If this is an electric-only sticker design, why the heck do they have greenhouse gas emissions listed? That will vary heavily depending on your local power generation.
     
    Can we start adding the “charge time” to gas vehicles, please? Makes the same sense.

  • avatar
    mike978

    I find it odd that the GM and Chevy Volt haters out there have suddenly gone quiet about Nissan over egging the Leaf range. It does 27% less range than they stated. I believe the Volt’s range is 40 as previously stated. So on the money.
    Yeah the 230mnpg figure is held up – fair point but it does all depend on the criteria used and at that point the EPA had no figure. Anyway you anti-GM and no doubt anti- federal Govt probably want the EPA to disappear. So no car labeling for you or other consumers.

    • 0 avatar
      PlentyofCars

      To repeat my above post.  Why does everyone assume 73 miles is where the battery goes dead.  No margin of safety.   If you are raped at night because the car went dead at 69 miles, can you sue the EPA..??
       
      I lived in northern Vermont and New Hampshire for 9 years.  I bought a new car right after I moved there.  I never turned on the AC once, until I moved to Maryland in year 10.   But the EPA assumes you always drive around with the AC on 100 percent of the time (even in New Hampshire below zero winters).

      BTW, in New Hampshire my average blended MPG was consistently 2 to 3 MPG higher than the highway only rating. In Maryland it was similar most of the year, because I only use the AC five months of the year, unless it is late at night, then I don’t use it at all. But the EPA assumes we all live in a very southern state and drive during the hottest time of day.
       
      Can someone with contacts at the EPA get an answers.   Are they driving the Nissan very aggressively with the AC and other electronics devices all on ??   If there a margin of safety built in. 

      How did Nissan drive the car ??

      I’ll bet there is a very logical answer for the lower mileage. If not, then I agree Nissan is dreaming.
       
       

    • 0 avatar
      Paul Niedermeyer

      PlentyofCars: Please reread my post regarding the Leaf’s range:
      http://www.thetruthaboutcars.com/2010/10/nissan-leaf-range-scenarios-anxiety-provoking-or-not/
      I made it very clear there that Nissan was using the EPA LA4 city cycle for its 100 mile range estimate. The LA4 cycle is obsolete; the EPA now uses a more difficult/realistic LA6 city cycle. That, combined with the highway cycle, is combined to create the EPA’s range estimate: 73 miles.
      I’ve been saying this like a broken record: EV range will vary much more than a gas car’s range, because of the intrinsic characteristics of EVs. It will be possible to exceed 100 miles, but it will also be very easy to get 55 – 60 miles :
      http://www.thetruthaboutcars.com/2009/12/ev-range-high-anxiety-normal-driving-may-cut-range-in-half/
      It would be quite difficult to vary a gas car’s range by 100%, without resorting to very extreme measures. It’s extremely easy in an EV, as drivers will find out.

  • avatar
    M 1

    But hey, this ain’t America if a consumer can’t glance at a label and say blah blah blah…
     
    Riiiiight, because your average consumer is supposed to spend every waking moment tracking and analyzing the detailed technical complexities of the automotive industry with the rest of us, and if they don’t, they’re just dumb old simple-minded Americans deserving only of your scorn.
     
    I bet one of those enlightened Euroopeean countries would just love to take you in. Bye!

    • 0 avatar

      Riiiiight, because your average consumer is supposed to spend every waking moment tracking and analyzing the detailed technical complexities of the automotive industry with the rest of us, and if they don’t, they’re just dumb old simple-minded Americans deserving only of your scorn.

      I seem to recall hearing older folks speak of a time when Americans took pride in keeping up to date on the latest developments in the world of the automobile, a machine that still occupies a hugely influential position in our society. Pardon me for bemoaning the demise of this interest.

      EVs are different from ICE cars, and you don’t seem to disagree with the premise that comparing the two directly could cause confusion (see: Volt, Chevy). So why bother assigning a pointless MPG number to an electric car other than to play to the lowest common denominator? I’m agnostic when it comes to the wisdom of consumers… the government’s decision is what I’m taking issue with.

  • avatar
    LimpWristedLiberal

    EPA MPG is a fantasy and if this hastens the end then I’m all for it.

  • avatar
    daga

    The interesting thing to me is does this now set the far right of the spectrum for all C segment labels.  i.e., a hypermiling Cruze at 42 MPG now looks like it is worse than average on the linear scale (since they only put the max and mix, not the median).

  • avatar
    thornmark

    >>GE is General Electric – when did it change its name. At this rate no company will want a G as an initial because loony people will insert Government in there regardless of facts.<<

    Loon Alert!!! A bailout you missed.

    For the uninformed, GE was the largest recipient of government loan guarantees through GE Capital.  The “Bank Rescue” rules were massaged to benefit GE. If not for those guarantees, GE may have collapsed just like GM.

    G stands for ……
    http://www.washingtonpost.com/wp-dyn/content/article/2009/06/28/AR2009062802955.html
     

  • avatar
    mike978

    Indeed Loon alert. I thought inserting Government into the name of a company (like GM) meant it was majority owned by the Government. Now it seems that the name is inserted if a company takes stimulus money (article from cato a poster linked to above). Well that is a lot of construction companies since we got some new roads oh and yes lots of tax cuts. If you don`t like the stimulus package then give back the $1600 you got from it.

    Thank God GE didn`t collapse. It seems the loons want lots of big companies to fail and then say “well true market capitalism ideology was best served, sod the millions unemployed”.

    I hope you are not doing any busines with Goldman Sachs (or should that be Government Sachs!), Wachovia, Bank of America etc since they all had a bailout – since repaid with interest to us. So we made a profit.

    • 0 avatar
      GarbageMotorsCo.

      So did GM, as they reported back in April!!!

      http://media.gm.com/content/media/us/en/news/news_detail.brand_gm.html/content/Pages/news/us/en/2010/Apr/0421_fairfax

      They owe nothing. We owe them for being honourable, honest, and sincere.

  • avatar
    Corky Boyd

    Ed,

    The reason for the 73 mile range is the battery capacity of the Leaf is 24 kWh.  With average electric consumtion of 34 kWh/100 miles, that works out to 71 miles, close to the 73 figure EPA comes up with.  It’s possible EPA tested the battery and came up with a slightly higher  battery capacity than Nissan has advertised. Might also be rounding errors.


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