• Mar 7th 2011 at 8:03PM
  • 17
Ever notice that the range numbers for some electric vehicles in Europe are quite a bit higher than the ones we see in the U.S.? Here's why this happens.
The United Nations Economic Commission for Europe (UNECE), which also covers Turkey, Israel, Russia, Canada and the United States, has the job of coordinating standards for fuel and energy consumption of vehicles. According to the protocol it has set for testing both pure electric and plug-in hybrid vehicles, energy consumption is to be measured when the vehicle is running solely on electric power at a constant speed of 50 kilometers per hour – that's a mere 31 miles per hour – without any acceleration or deceleration required. The electric range of the vehicle is then derived from the results. This figure is misleading because, aside from the obvious fact that real world driving requires acceleration and deceleration, the testing doesn't account in any way for wind resistance, which increases exponentially at higher speeds.

Here in the U.S., the EPA has no plans to use the UNECE's 31-mph consumption testing standard for electric and plug-in hybrid vehicles. Instead, it will use the same test cycle regular vehicles are subject to, but apply a snazzy new EPA sticker. Thankfully some automakers in Europe, like Volkswagen with its XL1 plug-in hybrid, aren't using this slow-speed testing procedure either, and instead choose to quote a more realistic consumption figure at double the speed (62 mph). The moral of the story here is before passing judgment on the range or electric consumption of an EV, make sure you understand what testing procedure was used to come up with the number.

[Source: Plugin Cars]

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    • 1 Second Ago
      • 4 Years Ago
      Not so fast in the condemnation of either the European measuring system, or ABG's reportage.

      Measuring the range of an EV is not an easy or simple calculation. I own a number of EV's (in five different countries) and the same model vehicles report widely differing ranges, depending on whose driving, the terrain and other factors.

      A great many factors come into consideration. Weather, road gradients, driving style, accuracy of charging, type of battery, weight of driver, weight of passengers, tyres, and tyre pressure, traffic conditions, rural/highway/suburban mix, and even the time of day, are just some of the factors that can affect an EV's performance dynamic.

      US driving conditions are often very different from Europe, so is charging.

      EV's tend to be more sensitive to these factors than ICE vehicles, rendering any assumed calculations inaccurate, when transposed to a specific driver.

      Even testing at a continuous speed is dubious since it makes no allowance for dynamics of the vehicle.

      It's not an easy calculation!

      A 'real world, real driving' calculation? Sure, but whose real world?

      This is where the 'range extended' vehicle like Volt, will prove a more satisfying experience for all but the most fanatical of EV oriented owners.

      So instead of indulging in a lot of head-shaking,lip-pursing, criticism of ABG, why not try to create an agreed workable standard measure ?

      Incidentally, until very recently, near all ICE performance specifications were rubbish also, but these were always accepted as being simply vague, optimistic inaccurate guidelines.
        • 4 Years Ago
        Jake, you seem to have missed the point. Volt owners, like Lexus hybrid owners, are not really a fussed about the accuracy of fuel savings.

        This is for three reasons, 1) their purchasers are not governed by anorak thinking,2) they can actually afford to buy the new technology. 3) Unlike you, these owners live in the real world, and base purchasing decisions on available products, not some vehicle that make exist in the future, which you couldn't afford anyway.

        If Tesla produce a remarkable new vehicle with a dramatically better range, simple solution!

        like thousands of car owners world-wide, just trade to a newer model?

        Now, whats so hard? Oh yeah, of course first you have to have a vehicle to trade!

        But, like most anorak-types, you missed the point of the post. How do you accurately calculate range?
        • 4 Years Ago
        Hey, an admonition from Grampus 3!

        Tsk,tsk, now that's the pot calling the kettle hue-challenged.

        Nevermind, if you actually read my post, you would see that my reply was an attempt to keep Jake relevant to the subject of the article.

        In the words of the late Humphrey Bogart, " I don't mind if you don't like my manners. I don't like them myself. They're pretty bad. I grieve over them long winter evenings. ".

        But then again, unlike you, I don't elect myself a spokesperson for others.

        I also notice you have failed, as usual, to contribute any useful, relevant or positive information to subject of this article.

        Why not try a relevant contribution?

        I shall eagerly await, your insightful analysis and learned dissertation on how you would solve the problem of providing a foolproof standard for measuring and quantifying the 'real world' range mileage of EV's.

        I would imagine such a standard would be able to encompass the dynamic I covered in my earlier post?

        In the advent of this unlikely occurrence, fear not, I shall be the very first with courteous and fulsome praise!

        C'mon, put me in my place! Leave your cracker barrel, be positive and relevant for a change?

        You can do it!
        • 4 Years Ago
        "A 'real world, real driving' calculation? Sure, but whose real world?

        This is where the 'range extended' vehicle like Volt, will prove a more satisfying experience for all but the most fanatical of EV oriented owners."

        Actually, I would say no, that would result in an even more unsatisfactory experience, because you feel you didn't get the AER you paid for. The AER is so low in PHEVs, that you will more regularly will go over it (it's basically designed with that in mind), which means you'll regularly notice if AER doesn't match specs. If you don't care at all about AER, it's unlikely you'll pay for the premium over a standard hybrid.

        So don't think PHEV drivers don't care about the range numbers. If you can't accept YMMV, then it's better to stick with a ICE car until the battery packs are large enough you don't even have to count range. Definitely getting there already (Tesla just announced today the first Model S's off the line will be the 300 mile versions).
        • 4 Years Ago
        Why you should feel entitled to make personal reflections about other posters rather than discussing the issue at hand escapes me.
        You obviously have an extremely high opinion of yourself not confirmed by your want of manners.
      • 4 Years Ago
      OK back to the subject:
      "constant speed of 50 kilometers per hour"
      I'd like to understand the logic behind publishing the results of such a test. You're only going to upset consumers when they get half the advertised range. People like to knock the EPA, but at least they're trying to be somewhat realistic.
        • 4 Years Ago
        My thoughts exactly. I mean, if you wanted to design a test that was guaranteed to have no resemblance to reality, you'd want pretty much the exact test described here.
        • 4 Years Ago
        To me the problem with this method is not the assumed speed (fairly reasonable for cars that are going to be used mostly in the cities) but the assumption of zero acceleration. This is assuming someone take the result as is and claims it is the actual energy consumption of the car.

        Note however that the actual range is said to be "derived" from the results of this tests. If there are no substantial non-linearities in the power train you can simply calculate the energy consumption at any other speed or acceleration (if you know the weight). So this methodology may be only slightly less accurate than that of EPA but more reproducible and flexible in adjusting to the actual use pattern of a given car.

        That's of course only a guess as the article doesn't say much about the actual procedure other than bashing it.
      • 4 Years Ago
      What Jonas Dalidd is wrong.
      What's done to measure electric range is described in normative document E/ECE/324 / E/ECE/TRANS/505 Rev. 2 Addendum 100 rev. 2 Amend. 2, Annex 9 ( www.unece.org/trans/main/wp29/wp29regs/r101r2a2e.pdf ).
      The range test
      1 - discharges battery on rollers (as described by Jonas) @ 50km/h for plug-in hybrid or 70 km/h for pure electric vehicules WITHOUT measuring distance achieved
      2 - charges the battery
      3 - discharges the battery following the classic ECE cycle ( http://www.unece.org/trans/main/wp29/wp29regs/r101r2e.pdf Annex 7 §1.1) until battery is considered empty. The distance achieved is measured and is considered as the electric range.

      The main reason why ECE electri ranges are bigger than SAE electric ranges is ECE cycle is less hard than SAE cycle. This explains also why vehicules show better fuel economy in ECE vs SAE.
      • 4 Years Ago
      "Ever notice that the range numbers for some electric vehicles in Europe are quite a bit higher than the ones we see in the U.S.?"

      Yep, I also notice how the MPG numbers for European vehicles are quite a bit higher than in the US. That doesn't stop ABG from repeatedly publishing them in headlines as if they were the same as US numbers.
        • 4 Years Ago
        Couldn't agree more with you for both 1st and 2nd post.
        • 4 Years Ago
        but, but.. the imperial amp hour is bigger... ;)
        • 4 Years Ago
        Among the 3 methods used to measure MPG and range, USA, European, and Japanese method, which gives the highest freeway mpg, city mpg, average mpg, highest and lowest range?
      • 4 Years Ago
      Slightly off-topic, but still on the subject of how government standard milage compares with real-world milage, I find the german website spritmonitor.de quite useful as it contains the real-world mpg's of more than 250,000 vehicles over 2.2 billion miles of driving. You can use the filtering mechanism to find out for example the fuel efficiency of any (mainly european) car.

      For example a new (136ps) Toyota Prius:
      real world mpg of 5.24l/100km, 54 mpg(imp), 45 mpg(us)
      EPA mpg: 4.7l/100km, 60 mpg(imp), 50 mpg(us)
      EU mpg: 3.2l/100km, 72 mpg(imp), 60 mpg(us)
      from http://www.spritmonitor.de/en/overview/49-Toyota/439-Prius.html?power_s=133&power_e=138&powerunit=2

      whereas an old style (75ps) Prius:
      real world mpg of 5.25l/100km, 54 mpg(imp), 45 mpg(us)
      EPA mpg: 5.1l/100km, 55 mpg(imp), 46 mpg(us)
      EU mpg: 4.3/100km, 66 mpg(imp), 55 mpg(us)
      from http://www.spritmonitor.de/en/overview/49-Toyota/439-Prius.html?power_s=73&power_e=79&powerunit=2

      The conclusions you might draw from this comparison are that the EU cycle is probably optimistic, but that both standards suggest that the new Prius should give significantly better fuel consumption over the old model, but in the real-world it hardly made any difference. My overall conclusion across a variety of vehicles are that government standard tests are only a rough indicative of the relative efficiencies of vehicles.

      The following URL links to a table of the top 100 cars on the database, the Prius is only 25th! http://www.spritmonitor.de/en/evaluation/economic_models.html
      Unfortunately for those of you residing in the USA the majority of the 25 better vehicles are not sold in the USA!
        • 4 Years Ago
        Interesting chart. Evidently displaying the superiority of diesel technology.

        Equally interesting, is the advertisement for a PRC Great Wall gas SUV ! (a little incongruous).

        But these charts are usually fairly inaccurate. the Australian Government Green car intuitive, published a list in 2009 list the top ten vehicles fuel efficient vehicles as:

        1 . Mitsubishi i MiEV
        2 . Tesla Roadster
        3 . Toyota Prius Hybrid
        4 . smart fortwo
        5 . Honda Insight
        6 . Suzuki Alto
        7 . Alfa Romeo MiTo
        8 . Holden Barina Spark
        9 . Volkswagen Polo
        10 . Suzuki Swift

        Never mind that both the iMev and Tesla were not available for sale in Australia, and that the locally produced Blade Electron EV, was inexplicably excluded.

        The site hosted by the Department of Infrastructure and Transport, refused to explain but the departments Minister, explained that only those companies who 'sponsored' the website were considered! The Minister later retracted the comment and advised that the matter would be looked into, and an answer sought. That Minister has since departed and the new Minister is 'looking into it"! (Don't hold breath).


        So it's my contention that many performance criteria 'lists', are often compiled using reports that in turn rely upon other inaccurate reports. Once cited many times, such inaccuracies become accepted truths.

        Inevitably, it's difficult to assess the true merits of an EV's range performance except by anecdotal evidence. (for whatever that's worth) .
      • 4 Years Ago
      The one that is completely out of of the measuring mainstream, is the one promoted by the Green Loons at EPA.

      If you compared the US legally certified and required methods with the EU and Japanese methods, the CAFE estimates produces numbers similar to those fuel economy measuring and estimating systems.

      But then the Green Loons at Obama's EPA would not be as able to prophesy Doom and Damnation. I actually would prefer that the window stickers offer the unchanged and documented methods leading to mileages of legally required CAFE, rather than their MORONICey and arbitrary and change-when-ever-some-EPA-fool feels like it, EPA mileage estimates. The EPA changed mileage estimates between the 2007 and 2008 model years and mileages changed between 6 and 13mpg for unchanged and unaltered models, universally downward. Did the EPA Loons ever document how those new EPA sticker mileage estimates were arrived at? NEVER!!!!!

      Just why should I NOT KNOW what the CAFE mileage estimate is, on those moronic window stickers? After all, it only what is REQUIRED BY LAW.

      • 4 Years Ago
      If this is how the new plug-in Volvo V60 aer is estimated at 50 I'm (31 mi), then it's a lot more underwhelming than I thought.
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