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Hybrid Cars to Get New Mileage Ratings 781

Posted by samzenpus
from the creative-math dept.
Skidge writes "Wired is running a piece showing the drastically reduced mileage ratings for hybrids after the upcoming changes in gas mileage calculations by the EPA. While the cars themselves aren't changing, plugging these new numbers in to the equation makes a hybrid much less cost effective: "The two top-selling hybrid vehicles, the Prius and Honda's Civic Hybrid, will lose 12 and 11 miles per gallon respectively from their city driving estimates." The new values come from more realistic testing; the old, over-inflated ratings were higher in part because the cars idled a lot, allowing the hybrids to completely turn off their engines. The new ratings should be more in line with what hybrid drivers are actually seeing."
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Hybrid Cars to Get New Mileage Ratings

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  • Sampling? (Score:5, Interesting)

    by powerpants (1030280) * on Monday May 14, 2007 @12:23PM (#19115597)

    It's important to have accurate mileage ratings on cars, and it's hard to understand how the EPA could be so bad at it. Why do they try to estimate instead of just sampling?

    Here's a simple approach: When a car comes in for an oil change, read the mileage rating stored inthe on-board computer and upload it to an EPA database. Problem solved.

  • by mdm-adph (1030332) <mdmadph&gmail,com> on Monday May 14, 2007 @12:27PM (#19115661) Homepage
    Problem is... NOBODY drives "properly." The new numbers released by the EPA are much, much closer to what 90% of drivers are going to get when it comes to fuel consumption.
  • Re:Sampling? (Score:2, Interesting)

    by aug24 (38229) on Monday May 14, 2007 @12:29PM (#19115715) Homepage
    Simple: because that would skew the sample towards mileage of people who either pay to have their oil changed or have it changed more regularly.

    Estimation is intended to produce a balanced result. Heavy on the 'intended', of course ;-)

    J.
  • by jkerman (74317) on Monday May 14, 2007 @12:30PM (#19115723)
    Far as i know they still test EPA mileage ratings by using an exhaust sniffer and rollers.... indoors.... it fails to account for AIR RESISTANCE!

    far as im concerned they should require someone to /actually drive/ the damn car through an /actual city/ and average the results to get the fuel rating.
  • by f0dder (570496) on Monday May 14, 2007 @12:34PM (#19115815)
    Help me out.. my understanding of a hybrid system was to bring performance to what are normally gutless high mpg 5spd low HP gas engines. If we only focused on high MPG then your 3cyl Geo Metro should of sufficed. But they sold poorly because they're gutless and for many reasons the market are not receptive to driving stick. A lot of folks keep bringing up the VW TDI diesels. But I looked at the performance numbers (ie 0-70 from consumer reports and the prius has better numbers). Are we to only focus on MPG becuase in the past they didn't sell well. Then again that was when gas was cheap. Will the market forgo performance for high MPG?
  • Huh? (Score:5, Interesting)

    by shoptroll (544006) on Monday May 14, 2007 @12:35PM (#19115833)
    I knew this was coming, and I'm a recent owner of a 2007 Prius. I'm currently averaging about 48 mpg on mainly highway driving, so I guess I'm doing better than most people out there driving these? Anybody who pays attention to the screen should be able to figure out to get the car running efficiently without needing to read up on hypermiling techniques (which will help if you want to go beyond some simple adjustments).

    So how are other cars faring with the new calculations? I'd imagine it should be proportional to the current numbers?
  • GreenHybrid (Score:2, Interesting)

    by mnemonic_ (164550) <jamec AT umich DOT edu> on Monday May 14, 2007 @12:35PM (#19115837) Homepage Journal
    Looks like these numbers agree pretty well with GreenHybrid's data [greenhybrid.com], which is composed of self-reported mileage numbers from hybrid owners. I'd still probably rely on GreenHybrid more because the EPA testing is just that, testing, not real world use.
  • Realistically (Score:5, Interesting)

    by bahwi (43111) <incoming@NosPam.josephguhlin.com> on Monday May 14, 2007 @12:36PM (#19115849) Homepage
    Realistically you do idle a lot. Red lights, idiot drivers, and traffic, and you're spending a lot of time idling. Not idling is not realistic. Even on highways you have some idling time, between dallas/houston(abt 4 hrs to 5 hrs) I idle about 30-45 minutes because of traffic and construction, and that's between the cities, where you can have even more traffic depending on what time. Traffic sucks, but it's a part of life. And yes, if you know how to drive a hybrid, you'll get mileage over what the EPA currently says(and drastically that over what it will say soon).

    And with the tax credits (I think ending this year or ended) it's been typically cost effective depending on what type of hybrid you get. A civic hybrid from last year would have paid for itself within 8 months with my level of driving, a 3000 premium over regular civics with 2000-2500(I forget where it was last year) back from the gov't means a difference of 500-1000 to make up, which is pretty easy with how gas prices went last summer.

    I hate these people who run the numbers and leave out other numbers. Tax Credits on IRS page [irs.gov]

    Yeah, they aren't guaranteed, but if you buy early you can get them pretty easily. Or who say "Batteries are expensive" when they have very long warranties that cover it. If you want to pretend to know what you're talking about, then do the proper research. If you want the most cost effective vehicle, gas wise, get a bike. You have to be comfortable with your car, hybrid or not, and if you don't like them don't get them. But don't make up fake reasons.
  • RE: Hybrids (Score:1, Interesting)

    by ShrapnelFace (1001368) <shrever@neuraldisruption.com> on Monday May 14, 2007 @12:41PM (#19115915)
    I used to be the Customer Relationship Manager at a Toytota dealership- I was happy enough to have a job given that I graduated college just as the bubble burst out here in Silicon Valley.

    Here are a few things that I have always known about Hybrids:

    #1 The best milage comes from the most conservative driving.
    #2 The batteries are more toxic than those in a normal car- and with each hybrid carrying between 5 and 7 of those batteries, they are not better for the environment.
    #3 The total energy used to manufacter a hybrid vehicle is higher than what it is for a regular vehilce of same size.
    #4 The depreciation rate is held up by popular opinion. This is true in all vehicles, but the steep cliff at year 6 is going to make most people unhappy, and the battery replacement at year 8 will be a very large cost to shoulder and may drive many people out of this market all togeather.
    #5 There is currently no plan for the recycling of these batteries.

    Most hybrids I see on the freeway are exceeding 70mph and are changing lanes frequently.
    What is on the window is irrelevant given the way that most people here in the US jump in their car and blindly drive these cars with the pedal on the floor.
  • by tarlos25 (1036572) on Monday May 14, 2007 @12:42PM (#19115955)
    As an owner of a 2005 Prius, I think they're full of crap. I regularly get an average (city/highway mix) of about 55 MPG. In the summer, it goes over 60 MPG for the AVERAGE, not just the city. If I only did city driving, it would be even higher. I'm not driving very conservatively, my driving habits are about the same as they were when I started driving. I keep up with the traffic around me, and sometimes go a little faster.

    Of course, when they lower the estimates, I'll just be beating their estimates by that much more.
  • Re:Sampling? (Score:3, Interesting)

    by guruevi (827432) <evi.smokingcube@be> on Monday May 14, 2007 @12:54PM (#19116203) Homepage
    My car (Buick) and a lot of other cars that I've seen keep a mileage rating in the dashboard. Currently an avg. of 27,4 mpg. But still, it would be skewed since I drive a lot and I drive fast (80mph+) making it to use more gas than the average person that buys said car.
  • by Xaroth (67516) on Monday May 14, 2007 @12:54PM (#19116207) Homepage
    My favorite line from the article has to be this one:
    "The new mileage estimates mean it will take longer to recoup that extra cost in money saved on gas."

    ...as though magically everyone's car suddenly starts eating up more gasoline just because the EPA changed their ratings system. It suggests to me that they should just revise their estimates upwards, so that everyone can save that money they'd be spending on gas. If we made it high enough, we could eliminate our dependance on foreign oil! Clearly, the EPA is in it with big oil to keep the little man down. Jerks.

    The article is full of lines like this. For example, they have some random guy quoted in an email as saying that he didn't trust the Prius ratings and that a Corolla got just as good of mileage. They have a table listing various MPG ratings from the EPA, so one might think that including the Corolla to corroborate this random guy's story would be a good idea. Not this author, though. I mean, that aside from picking some random guy from the internet to use as a key quote to support the idea that the EPA guidelines aren't precisely commensurate with people's actual results.

    All that said, I suppose I'm just expecting too much from Wired. ;)
  • Re:Sampling? (Score:2, Interesting)

    by ArcherB (796902) * on Monday May 14, 2007 @01:02PM (#19116399) Journal
    I think the parent is referring to those computers with built-in MPG displays. The oil-change computer would grab THAT displayed number, which is readily available.

    Unfortunately, I can't say how accurate those things are. My wife's minivan as well as her last vehicle (a 4-runner), both have this display. Both pad the average gas mileage by a mile or two. I know this because we always reset the trip meter after every fill up. Whenever we get gas, we divide the number on the trip meter by the number of gallons we used to fill the tank. While the display usually reads about 21 mpg, we calculate 19-20 mpg. These differences are consistent across both vehicles and have been consistently off at every fill-up.

    So either the car miscalculates the average mpg or the odometer is wrong.
  • Re:Sampling? (Score:3, Interesting)

    by klubar (591384) on Monday May 14, 2007 @01:05PM (#19116469) Homepage
    The computer-based MPG aren't that accurate because they don't account for evaporative loss. E
  • Re:Diesel! (Score:2, Interesting)

    by Anonymous Coward on Monday May 14, 2007 @01:05PM (#19116477)
    You have a good point. The restrictions on the sale of Diesel cars are ridiculous. It's a much better option than a hybrid, and the engines last a long time. Maybe too long. If there is one thing the manufacturers don't want it's a car that runs 300,000 miles.

    We allow a seemingly unlimited number of Diesel trucks on the road; I see no reason why the cars are so heavily regulated. I suspect that if more than just the German manufacturers were making Diesel cars, the EPA regulations would vaporize faster than a Ford Pinto gas tank. Are we interested in fuel economy or not? I really wonder.

    If US consumers had to pay the same fuel prices as Europeans, they would warm up to Diesel in a hurry.
  • by GreyPoopon (411036) <gpooponNO@SPAMgmail.com> on Monday May 14, 2007 @01:14PM (#19116645)

    The US automakers have been fighting to keep the current standards for decades so that they can tout the "Great Milage" that their cars have. Now that something has come along that looks even better that the standard (read fossil fuel only) autos look worse, they probably have done some back door lobbying to change over to this new formula.

    I'm not sure this is completely true. For normal gas automobiles, I have encountered fuel economy very close to the EPA estimates, so I don't think there was any reason for the US automakers to "fight" the current standards; they seemed to be adequate. Now, the US manufacturers were "late" to market with Hybrid vehicles, and I can think that for the last several years, they would have been fighting hard to CHANGE the standard rather than keep them the same. Perhaps that's what you meant (IE, fighting the last few years and finally getting success) But as we all know from actual performance of Hybrid vehicles, there has been significant reason to change the ratings process. I can tell you from my experience buying cars (and looking at both Toyotas and Hondas) that, at least from the perspective of the dealerships I visited, they have been hoping and praying for change. They were very well aware that Hybrid cars were not achieving the stated EPA ratings. And they were also aware that even though the short term effect was a boost in sales, the long term effect was a dissatisfied customer. Any good dealership is highly interested in repeat customers, and they know they have to balance that with selling the car for the highest price they can. They don't want something like false fuel economy ratings to interfere with the customer relationship. I know that in the case of two dealerships that I visited, when I expressed some interest in a Hybrid vehicle, one of the first things that the sales people told me was that although the fuel economy was significantly better, in most cases it would not be nearly as good as the EPA rating indicated. In fact, one of the sales people told me that he would like to remove the EPA ratings from the car sticker, but that they weren't allowed to do so.


    So actually, I think that ever since Hybrid vehicles hit the market, it has been in EVERYBODY'S best interest to adjust the rating standards, but the EPA has been slow to respond with improvements. But don't go blaming the EPA either. Keep in mind that they had to come up with one standard that applies to both conventional and Hybrid vehicles. The basics of that might be simple, but the effort to come up with something that all the manufacturers will agree with was probably a lot more involved.

  • by bastia (145202) on Monday May 14, 2007 @02:05PM (#19117695)
    I found that last comment from the article a bit odd. They've dropped the rating on the Prius to 48/45/46. I suppose that I do a mix of driving: some local start and stop around 35 MPH, a lot of commuting on interstates (65 - 80 MPH) and state highways (50 - 60 MPH).

    Over the past two years, I generally average much closer to 50 MPG. During the winter (worse battery efficiency), it's closer to 45 MPG. During the the rest of the year, it's generally more like 52 MPG. I don't drive like a maniac, but I'm not super careful about squeezing every last bit of efficiency out of the car. I'm not sure what you'd need to drive like to pull the Prius numbers much below the new figures.

    But, yeah, the new numbers look more realistic than the old numbers. :-)
  • Re:Sampling? (Score:3, Interesting)

    by drinkypoo (153816) <martin.espinoza@gmail.com> on Monday May 14, 2007 @02:17PM (#19117889) Homepage Journal

    This is a rather important point many people don't understand. Driving the speed limit and driving defensively save gas.

    What you apparently don't understand is that this varies from vehicle to vehicle.

    I have owned two vehicles now which get their best mileage around 80 mph. 1989 Nissan 240SX, which is one of the most aerodynamic vehicles on the planet (0.26cD) and a 1981 Mercedes 300SD Turbo Diesel.

    Aerodynamics, gearing, and torque curve combine to define the most efficient point. For some vehicles, especially trucks and vans, they are most efficient around 55 mph. Most passenger vehicles are most efficient from 60-65 mph.

    These numbers have actually changed over time as speed limits have changed, but there are occasional freak cars that don't seem to correspond to anything.

    In any car, the way to save the most fuel is to press the accelerator as little as possible. Actually, that's not precisely true; the most efficient way is to accelerate at about 3/4 throttle, then drop into neutral and coast, bouncing back and forth between about 35 and 65 miles per. But that's generally unsafe on public roads.

  • by Hatta (162192) on Monday May 14, 2007 @02:32PM (#19118123) Journal
    No one can guarantee you can maintain your current lifestyle indefinitely. Growth curves [tamu.edu] are sigmoidal. We are in the exponential phase right now, but that doesn't last forever. Resources are finite, and growth must eventually approach an asymptote. You can stick your fingers in your ears and deny it, but that doesn't change anything.
  • by SoCalChris (573049) on Monday May 14, 2007 @02:37PM (#19118273) Journal
    I would argue that windows have become far less efficient at cooling car interiors than in the past.

    Have you ever driven an older car that has wing windows? Or how about one that has vents that you can open, that let fresh air blow right on your lap/torso area.

    My first car was a 57 Ford sedan that had both of those, and growing up in a desert area of Southern California, it did a good enough job of keeping me cool that I never wished for a car with air conditioning.

    Modern cars are very noisy with their windows open, and don't provide a good stream of fresh air moving through the cabin without using the climate control system.
  • Re:Sampling? (Score:2, Interesting)

    by steevc (54110) on Monday May 14, 2007 @03:39PM (#19119533) Homepage Journal
    I drive a diesel manual Vauxhall Zafira 1.9L, 120ps. The quoted economy is Urban 37.2, Extra-Urban 55.4, Combined 47.1mpg (UK). I have averaged 46mpg over the last 3 years, so that's pretty accurate. My daily commute is 25 miles of motorway that always slows to a crawl in places with the rest in variable London traffic. I drive for economy, anticipating when I need to slow down and not accelerating too hard. Recently I've taken to keeping to around 65mph on the motorway rather than around 70mph when traffic allows. For the last couple of tanks I've averaged almost 50mpg. That's about 41mpg (US). I don't think that's bad for a car that can carry seven people.

    The time is coming when we will replace our old Rover 1.6 manual petrol (37mpg). I'll be looking for something that uses less than the Zafira to use for my commute. With the price of fuel rising again in the UK it has the potential to save me a heap of cash. Diesel looks likely to go over a pound soon.
  • by Technician (215283) on Monday May 14, 2007 @04:06PM (#19120127)
    In fact, hybrids do much better in heavy traffic because under a certain speed (35 Km/h for the Prius for instance) it's just running on batteries.

    In the escape Katrina traffic which was at a standstill much of the time, many people ran out of gas within 60 miles of New Orleans because they were traveling at less than 2 MPH. At 2 MPH a Prius can run for days (literaly) on a tank of gas. (keep the AC off)

    I know this is possible as I have put an inverter in mine and use it for emergency power. In an ice storm here in the Pacific NW, we ran off the car running the fridge, TV, some lights, the blower on the wood stove, and the computer for 3 days. Dial-up internet still worked. We used less than a half tank of gas. Sitting in traffic not moving much, we would have had about the same gas consumption rate.
  • by Anonymous Coward on Monday May 14, 2007 @04:12PM (#19120239)
    I have a 2006 Civic Hybrid too (in the bay area, driving it for almost a year now). I get an average of 42mpg when I'm not trying, and was at 46-47mpg when I was trying really hard. A week ago I realized that slow starts aren't good, because you're keeping your engine on longer. Instead, a quick start hits your engine the same amount but for less time. Thus, you're at a high speed sooner which uses your battery to sustain it. I've only started that style this week, but Prius owners tell me it makes a big impact on their efficency.
  • Re:Realistically (Score:1, Interesting)

    by Anonymous Coward on Monday May 14, 2007 @04:13PM (#19120243)
    I ride my bike to work 3 times a week...where's my tax credit?

    The logic for tax credits is flawed. Rather than incent people to buy more fuel efficient vehicles with tax credits, you should impose additional taxes (registration fees, gas taxes, etc) to punish those who don't choose fuel-efficient vehicles. Taxes in other areas can be lowered to keep the current level of taxation. If the vehicle registration fee for a Hummer-style SUV was $10,000/year, a minivan $1000 and a hybrid $200, there'd be no need to offer a tax credit.

    Gas taxes make even more sense because you want to discourage the use of gas in any form. It's far more fuel-efficient to drive a Hummer to work for 3 miles away than it is to drive a hybrid to work from 40 miles away.
  • Re:Sampling? (Score:2, Interesting)

    by itof500 (239202) on Monday May 14, 2007 @04:25PM (#19120477)
    "Driving interstates at 55 does *not* save gas. "

    Actually, driving 55 on the interstate does save fuel. I keep complete records of every tank of fuel, miles per gallon (US) and driving conditions. My ride is a 1997 Jetta diesel (manual) that I bought new and still drive (140k miles). Each figure comes from a long trip on the interstate where I was able to maintain the listed speed for the full tank. Test drives are all in the summer and repeated (over the years) with an N of at least 3.

    70 mph - 45 mpg
    65 mph - 52 mpg
    60 mph - 56 mpg

    I've not had the opportunity to do a whole tank at 55 mph, but I think that the trend is clear that driving slower than 70 mph does save fuel.

    duke out
  • by klausboop (322537) on Monday May 14, 2007 @04:25PM (#19120479)
    Bah. Fuel efficient cars (including hybrids) reduce our dependence on foreign oil. I'll happily pony up the extra $$ for that, even if I'll never "regain" the expenditure with savings at the gas pump.

  • by onemorechip (816444) on Monday May 14, 2007 @05:02PM (#19121147)
    The new mileage ratings were posted some weeks or months ago, so this article is late to the party. But it still gets it wrong on a few counts. Mostly not factually wrong, just wrong on interpretation. For instance:

    Hybrid vehicle performance was previously overestimated partly because the tests included vehicles' idling for long periods, causing many hybrids to shut down their engines to conserve fuel. The old testing methodology registered "a higher fuel economy for hybrid vehicles than is achieved under typical driving conditions," according to EPA documents.

    Linking these two statements into one paragraph suggests that shutting down the engine while stopped causes the hybrid to perform better in the test than in the real world. That's not true; the same benefit is derived by the hybrid in real-world driving (most of the stops in the old EPA test were briefer than a typical traffic light stop -- not "long periods", a factual error in the article). In reality, a full hybrid such as the Prius also stops the engine while coasting (if the speed is low enough to allow this), but the EPA didn't seem to think it needed to do anything to remove this advantage from the tests.

    The earlier test methodology ran the cars through a certain speed profile (one profile for "city", the other for "highway"). The results were known to be optimistic because (1) A/C was not on during the test; (2) most people drive faster than the profiles; (3) in many people's "city" driving there are more frequent stops than in the test, although this varies with location; (4) probably a host of other reasons. To compensate for these factors, the EPA applied fudge factors to the result, derating the MPG to better match real-world conditions. The same derating was applied regardless of the type of vehicle, so some cars get more optimistic ratings than others.

    The fix to this inequality was to change the test so that the derating factors could be eliminated. The profiles were changed, and things like cold engine starts and the use of A/C were taken into account.

    But, if you change the amount of time the car is stopped during the test, this would have no effect on the outcome for a Prius or similar hybrid (I'm not sure if the Civic hybrid shuts off the engine while stopped; I seem to remember reading that it doesn't). It doesn't use any gas while stopped, so the denominator is not increased, but it doesn't go anywhere during the same period, so the numerator is not increased. For a non-hybrid, there is a definite increase in measured MPG if there is less time when the engine is idling, so the ratings gap between hybrids and non-hybrids is reduced.

    Consider a hypothetical example. Car A is a hybrid and gets 65 MPG under the old city test; with the derating factor applied, it gets 60 MPG (roughly the numbers for a Prius). Car B is a non-hybrid that gets 32.5 MPG on the cith test, derated to 30 MPG. Under the new test, the conditions are tougher (higher speeds, A/C is on part of the time, etc.), so both cars see a drop in measured MPG. Say Car A now gets 48 MPG and Car B gets 27 MPG (Car B sees a lesser drop because, although the test is tougher in other ways, it doesn't have to idle as much, a benefit that is meaningless to Car A). No derating is applied, so these are the published numbers. Car A's EPA rating drops by 20% from the previous method, and Car B's drops by 10%.

    Another factor is that running the A/C takes up a bigger percentage of the fuel consumption in a car with higher fuel economy. That's not hybrid-specific; any non-hybrid that is in the 35-MPG and higher territory is going to see a big difference between A/C and non-A/C operation.

  • Re:Sampling? (Score:2, Interesting)

    by Doppler00 (534739) on Monday May 14, 2007 @07:53PM (#19123519) Homepage Journal
    Coasting to the red light would be nice if it wasn't for all those jerks that think they have to accelerate, pass me, and slam their brakes in front of me all while the light is still red. And I'm afraid that around where I live, if you don't drive aggressively enough you might be shot for making those jerks mad at you.
  • by Anonymous Coward on Monday May 14, 2007 @08:56PM (#19124211)
    I personally do not hate Hummers -- in fact I love most SUV's because of their size...

    I do not own or drive my own car -- I walk on two crutches and do not use a wheelchair. I HATE small cars -- because they have door and entry way structures built for an F-ing dwarf or midget. A full size pickup truck or SUV is at a height and has a wide enough doorway for me to get into and out of easily...small cars tend to be much lower to the ground and are not easy to get into or out of at all... 60's and 70's full size sedans are fairly easy to manuever...but still a pain because of ride height...but ride height can be tricky -- a really beefed up 4x4 will be jacked up so high as to be near impossible to lift myself into...People who mandate a one size fits all approach to vehicles for any reason -- suffer from ID10T errors...

  • Re:Sampling? (Score:2, Interesting)

    by jafiwam (310805) on Monday May 14, 2007 @09:03PM (#19124297) Homepage Journal
    Mythbusters did an episode on this issue using Mountaineer vehicles, a track, a steady speed, etc.

    It came out that open windows beat air conditioning by something like 10 miles on a full tank of gas. In other words, the windows open vehicle went an additional 30 laps after the air conditioned one ran out of gas.

    The "computer estimate" model gaging air flow to the engine indicated about 11 mpg for both, air and windows open, but that won't catch the computer running a richer mixture to push more... only a difference in RPM and gearing ratios.

    Something might have gone wrong on their test, but my experience also reflects that air conditioning sucks up way more gas than open windows at least in my car.

    Whomever started saying that air conditioning is more efficient didn't TEST it, and if they did, one a vehicle that had super-efficient air conditioning and not an SUV, or maybe they did use the gearing (but then leave that out) "some vehicles at X gear and Y rpm are more efficient with air on and closed windows".

    Either way, I don't believe the air conditioning thing anymore.

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