Slashdot Mirror
Hybrid Cars to Get New Mileage Ratings
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."
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.
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!
/actually drive/ the damn car through an /actual city/ and average the results to get the fuel rating.
far as im concerned they should require someone to
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?
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?
Insert Sig Here
Looks like these numbers agree pretty well with GreenHybrid's data, 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 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
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.
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.
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.
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.
GreyPoopon
--
Why is it I can write insightful comments but can't come up with a clever signature?
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.
No one can guarantee you can maintain your current lifestyle indefinitely. Growth curves 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.
Give me Classic Slashdot or give me death!
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.
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.
The truth shall set you free!
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.
Some of you already have those cute little shirts on that say disco sucks, right? That's not all that sucks.-Frank Zappa
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.
But, I wanted socialized health insurance!