Misplaced Pages

Revision as of 18:36, 7 May 2008

Raison d'etre

This article was created by merging sections of Fuel economy in automobiles that overlapped considerably with Ecodriving, Nempimania, and Hypermiler together into a single centralized location. All three terms covered nearly identical concepts, the only significant difference between the three being where they are used. Note that some handy sources for future use may be found in the failed AfD discussion for Hypermiler, found here: Misplaced Pages:Articles_for_deletion/Hypermiler MrZaius 10:06, 3 June 2007 (UTC)

Content suggestion

There is a good deal of information at WikiCars that could be merged into this article to make it more complete. Dkbryant 05:10, 7 June 2007 (UTC)

Perhaps, but keep in mind that completeness, in this case, is defined as reaching Misplaced Pages:Featured article status, rather than generating a complete list of fuel economy tips. This involves breaking down the most prominent techniques into detailed, well sourced, verifiable statements demonstrating how/why they work, who endorses/created them, etc and covering the history of the concept, preferably going back at least as far as the World Wars. MrZaius 20:46, 7 June 2007 (UTC)

...The "Fuel Selection" Section

contains completely bogus "information." It is very well established that a given gasoline engine can provide more power when it is built with a higher compression ratio, that is the combustion chamber is smaller than initially. This increases the need for higher octane fuel to prevent engine damaging knocking. The BTUs in cheap gasoline and expensive gasoline remain about 120,000 BTU per US gallon. (Ethanol has about 85,000 and Diesel Fuel is near 140,000)207.178.98.52 19:25, 6 August 2007 (UTC)

P&G / FAS Information:

I see significant problems in the descriptions of P&G and FAS.

Most importantly they are described as techniques for hybrids, whereas they are at least as useful on non-hybrids if not more so. Implementation is a bit different for a hybrid as you need to trick the car in to disengaging both the internal combustion engine and hopefully also the electrical charge/discharge activity. For a conventional car you just put it in neutral and either shut off the engine or not.

As P&G vs. FAS are essentially the same we need to show that. However the basic concept needs to be spelled out much more clearly than it is.

Also P&G / FAS should be detailed with more specific information for use with hybrids, and for conventional vehicles with standard or auto transmissions as the application will vary.

I think I could write something better than what we have now but I'm still a noob here at Misplaced Pages.

Within this discussion I'd like to reference the post below (not by me). It's significant in that it shows clearly the value of pulse & glide vs. steady state speed. http://www.cleanmpg.com/forums/fuel-economy/t-very-preliminary-non-hybrid-sgii-results-pg-speed-effects-accel-climbing-4819.html

Comments?

Brucepick 12:10, 9 June 2007 (UTC)

The content we have now was from a couple of articles that were advertisement-like in tone, hyping hypermiling and ecodriving, and a clunky two or three paragraph section-stub at the main fuel economy article. Feel free to completely rewrite this article, if you think you can do so without sacrificing any valid information, but please keep in mind that the goal, as stated above, is creating a strong encyclopedia article, not a howto guide or book on maximizing fuel economy - For that, you'd be better off looking at the wikicars site mentioned above or wikibooks. It seems to me that we need most desperately is thoroughly cited, verifiable coverage of who recommends what and why. MrZaius 16:02, 9 June 2007 (UTC)

Flora_Poste 12:51, 21 August 2007

I agree more or less with Brucepick: I think that what is most needed on this page is a well referenced list of the various eco-driving techniques that have been proposed and investigated, with quantification of the impact of each technique. There is validity in describing types of eco-drivers as a secondary topic. Discussion of hybrid cars belongs elsewhere, as eco-driving is about the style of driving, and car maintainance - not the car. 12:51, 21 August 2007

P&G seemed inaccurate to me, inasmuch as it strongly implied that the technique only works for some hybrids, whereas the technique predates hybrids, so I rewrote it. It's not perfect, there's a lot more information I don't have the time to track down (references to P&G being utilized as early as the 1950s, ideal speed ranges, etc - perhaps this should eventually get its own article, I don't know, I'm a bit of a noob wiki editor), but it's better than what was there by a fair amount. Ravaet (talk) 10:07, 30 December 2007 (UTC)

Factually Inaccurate

When accelerating, the engine should be kept in the peak of the torque curve, 
this is usually at around 75% throttle Citation needed. A slow acceleration is less efficient.

This is completely wrong, in terms of fuel economy. The maximal fuel economy is achieved at a fairly slow rate of acceleration. The car should be in its efficient powerband (RPMs not too low, not too high) but there's no reason to suggest that a certain throttle position is optimal for all cars.

Actually, the quoted statement is correct. This long report includes an engine efficiency map; if you look at other they are broadly similar. Efficiency varies weakly between about 50% and 100% throttle; below 50% throttle it drops rapidly.Ccrrccrr (talk) 14:01, 19 January 2008 (UTC)

Optimal efficiency can be expected while cruising with no stops, at minimal throttle and with
the transmission in the highest gear. For most cars these conditions are satisfied at a speed
of approximately 35 miles per hour.

Also wrong, the EPA has published data that shows peak efficiency is somewhere around 55-60mph for most cars. This is the point at which air resistance begins to become a significant factor.

These are just a couple examples, but the whole article is full of unsupported and highly questionable claims to anyone with a basic knowledge of physics. Suggest the article be rewritten or simply taken down, in its current form its only function is to misinform. Crouchingturbo 20:26, 23 August 2007 (UTC)

The link above to EPA "published data" is not really data, at least not that I could find. If you dig deeper and read EPA testimony on speed limit laws, they admit that their data isn't really very useful for that. So let's try to find some actual data. Here's one data set.Ccrrccrr (talk) 05:22, 19 January 2008 (UTC)

Here's information on the factor used in California models, but that's not ideal, since it's over a whole cycle, not a steady speedCcrrccrr (talk) 05:26, 19 January 2008 (UTC)

Here's a PhD thesis that uses data collected from a large assortment of vehicles to build a model. It includes graphs comparing data to the model. The data in Fig. 5-7 shows that fuel economy varies little in the 35-to-55 mph range, gets worse quickly above 60. (Considering the upper right plot, which is for zero acceleration.) MODELING LIGHT DUTY VEHICLE EMISSIONS BASED ON INSTANTANEOUS SPEED AND ACCELERATION LEVELS, kyoungho Ahn, 2002. —Preceding unsigned comment added by Ccrrccrr (talk • contribs) 13:52, 19 January 2008 (UTC)

Fuel Choice is Irrelevent

Currently the article reads:

The efficiency of a gasoline engine is related to the fuel's octane level. Differences in cleaning agents between brands of fuel and between loads of unbranded fuel can also have a noticeable impact Citation needed. Drivers may also weigh the fuel efficiency of multiple fuels for flexfuel vehicles and diesel vehicles, as the use of biofuel can result in marked changes in fuel economy in the same engine Citation needed.

A car requires the type of gasoline it was designed for, choosing a fuel for its octane content is unrelated to maximizing fuel economy. A high compression engine needs high octane fuel to prevent detonation. A lower compression engine doesn't, and giving it higher octane fuel is a waste.

I find the claim that differences in fuel cleaning agents actually has a noticeable affect on fuel economy unlikely, but I have no support. Gasoline is generally all taken from the same pipe, where distributors pick up a load and add chemical gimmicks designed to differentiate the brand... LostCause 04:08, 26 August 2007 (UTC)

Speaking only from experience, I ran several tanks of each grade of fuel through my Geo Tracker, and found I had the best mileage with mid-grade (89 octane) gas, good enough that it countered the slightly higher price. My theory is that lower grade gas causes the motor to ping slightly, so the computer advances the ignition timing, which is slightly less efficient. I would advise others to do the same thing, test each grade of gas in their car, rather than taking it on faith that one grade or another is the right one. —Preceding unsigned comment added by 64.65.77.28 (talk) 06:55, 12 March 2008 (UTC)

U.S. View?

While modern hybrids come with built-in trip computers which display real-time MPG most gasoline powered vehicles do not have this as a standard option (although some luxury cars do).

Is this true in general, or only in U.S. I think that most cars sold in Europe have a built-in trip computer. --Jirka6 12:33, 18 October 2007 (UTC)

Slight problem with interpretation of fig 5-7

Modeling Light-Duty Vehicle Emissions Based on Instantaneous Speed and Acceleration Levels, , kyoungho Ahn, 2002 Virginia Tech PhD Thesis, Fig. 5-7

Is a great reference but we somehow need to make clear that although the fuel consumption at a given speed increases as the acceleration is increased, this may or may not be more efficient - more work is being done as the vehicle gains more KE per second.

While I'm at it, you'll normally see worse fuel economy overall if you acccelerate harder up to the same target speed, what you really need to do is to accelerate harder to a lower target speed, to maintain the same average speed. Greg Locock (talk) 01:05, 22 January 2008 (UTC)

I was referencing it just for the 0 acceleration case. Maybe I should add more explanation in the footnote.Ccrrccrr (talk) 01:45, 22 January 2008 (UTC)

Source problem

I'm seeing a number of sources listed there which are blogs or other self-published sources. These don't meet WP:V and need to be cleaned up and replaced by reliable sources.--Crossmr (talk) 14:27, 8 February 2008 (UTC)

coasting out of gear

The whole discussion of coasting out of gear should be moved out of the accel section, into its own subsection under specialized techniques.Ccrrccrr (talk) 12:51, 19 February 2008 (UTC)

Recent reverts

I don't want to be getting into a revert war here, but the 01:47, 26 March 2008 version by Mikiemike seems to be in error. It has the content and figure in Fuel_economy-maximizing_behaviors#Understanding_Energy_Losses repeated twice. It was made on the basis of restoring my "unexplained and unsummarized deletions" but if you look at the page history, my edits do have summaries and the deletions are explained as moving material. If you don't like my reorganization, please explain why not, and move the material back, rather than having it repeated.

What we might need to discuss here is the safety section, which was deleted on the grounds that it was original research. That seems true to me--if it's not original research, the burden of proof is on somebody who claims it's not to provide sources. Ccrrccrr (talk) 03:12, 26 March 2008 (UTC)

Ccrrccrr, your entire edit summary just states: 'deleting section moved below', without saying what section you're referring to, or why it was deleted. --Mikiemike (talk) 15:22, 27 March 2008 (UTC)

I deleted the safety section because it was not sourced. I know that normally you just tag this things, but if you read that section, it seems to attempt to convince the reader to try out turning off the engine while driving which is a terrible idea. Brusegadi (talk) 03:33, 26 March 2008 (UTC)

Maybe half the material on Misplaced Pages is unsourced. Are you going to delete half of Misplaced Pages too? You know, it's sometimes better to source it rather than start over from scratch. Turning the engine off is not a concept that I made up. There are a lot of websites that talk about people who use this "Fuel economy-maximizing behavior". Apparently they survived to write their webpage, so apparently it doesn't have the 100% suicidal rate you claim, a conclusion which is based on your original research! Anyway, because there are sources that say people turn the engine off, that makes it relevant to the article, and it doesn't matter whether you think the behavior is a good idea or not. I'm not completely biased, because I did mentioned the reasons I found in my research why it may be unsafe. Are you going to delete the article on suicide too, because you don't think it's a good idea and you don't want to risk convincing someone that it's a good idea? No, of course not! You would re-word it, not delete it. So to use <personal dislike> as a criteria for deletion is seriously flawed.
The goal here is to give people all the info, so they can reach their own conclusion. It's not your job to censor information. To censor info is just as manipulative as trying to convince someone of something with biased info. If you think the language is an 'attempt to convince', then the language can be improved.
Anyway, there are numerous factors that influence safety. Some are subtle, others are not so subtle. Arriving at a reasonable conclusion requires all the facts, and a study of the issue, and those conclusions should be left for the reader to decide for themselves, and not left to the editors (like you or me) to decide.
The safety of these behaviors are obviously an important issue. You yourself say that it's a 'terrible idea', and you use that as a reason to not engage in those behaviors, therefore this is a good reason to cover the issue in the article. You had the opportunity to explain why turning the engine off might be unsafe, but you missed your chance when you allowed the entire section on safety to be deleted. Currently all the readers are left in the dark about all the safety advantages and disadvantages of these behaviors. So can we get a vote on this? Who thinks a section on the safety issues should be in the article, if the material is referenced?

The article got messed-up when people simultaneously moved sections and then deleted them, without explanation or discussion, plus made other edits at the same time. All I did was click <undo>, and that should not have caused duplicate material unless somebody did copy-and-paste on a section, instead of cut-and-paste.

(See also this discussion: User_talk:Mikiemike#Safe_driving)
Mikiemike (talk) 15:22, 27 March 2008 (UTC)

Then please bring in the reliable sources that discuss this technique, I ma sure that the article on suicide has many since it is a practiced studied in many fields, on the other hand, your drivign technique seems to be right out of Joe's blog. Furthermore, other stuff exists is not an argument; yes, there is much stuff in wikipedia that is not cited and we keep it because we have not enough labor to remove it. Really, some articles read like the insane are running the asylum. So, since the technique sounds fringe (I could not find any mention of it in respectable sources), I will not tag it, I will just remove it since wikipedia is not a vehicle to spread new ideas, it is a vehicle to explain established ones. Brusegadi (talk) 16:58, 27 March 2008 (UTC)

Brusegadi,
There are plenty of subjects that are real, particularly in pop culture, which can be difficult to find reliable sources for, and there are plenty of subjects that are established in practice, but which are rarely written about in what you call "respectable sources".
Coasting in neutral is not a new idea. I listed some sourced facts, and you deleted them all. I see nothing wrong in with adding relevant information that is reliably sourced. Controversial topics inevitably become just a list of facts. There's a difference between listing the facts, and WP:SYN which has to do with drawing original conclusions. If you think I'm drawing an original conclusion, then mention that here, or delete that statement only, rather than deleting the entire section, the rest of which is legitimate.
This is not a "how to" manual for driving any more than the suicide article is a how-to manual! Rather, Misplaced Pages consists of articles that covers all the issues within each subject, whether recommended or not. Also, blogs are part of pop culture, so there needs to be a distinction between referencing pop culture and referencing what you call "established" practice. The only reference in my recent addition that might be construed as a blog, is cited as an individual account of hypermiling, tailgating and road rage. What's wrong with that? Even legitimate sources use information that is based on talking to the man in the street. WP says that material doesn't have to be pure truth, which is impossible to determine anyway, it just has to be "verifiable". Anyway you deleted all of my credible references. Are you a discriminating "editor" or a non-discriminating "deleter"?

Mikiemike (talk) 20:38, 28 March 2008 (UTC)--

You are attemting to legitimize your edits by quoting government sites that are about driving in frozen roads, thats WP:SYN. You seem to not get this and I think that you also think I have somethign against you, so I will ask for a third opinion. Brusegadi (talk) 21:10, 28 March 2008 (UTC)

The things you say about what I am "attempting" to do is your perception and opinion. You're entitled to that, but WP is another matter. Some people say driving in neutral is totally illegal and totally unsafe and should never be used. Other people say they do it all the time and it's not that dangerous. So the issue is what should the editors do about this controversy? What I've done is in between these two extremes. I've said: on the one hand it's illegal and can be unsafe in some circumstances, while on the other hand there are instances when it is legal to drive in neutral and it is considered safe. If that is not balanced enough for you, then help make it more balanced. I strongly disagree with anyone who thinks that censoring a POV resolves the controversy. I reject that mentality completely.
An example of WP:SYN would be to say that coasting in neutral on frozen roads is okay, so it's safe to drive in neutral all the time. This is not what I said. I think you (Brusegadi) jumped to this conclusion, and assumed that I was implying that. Obviously there are similarities and differences. But to simply say that coasting in neutral is illegal and should never be done isn't telling the whole story. So it wouldn't be right to delete that either. Instead of deleting it, improve on it, or suggest something better.
--Mikiemike (talk) 18:35, 29 March 2008 (UTC)

I think we are moving in a good direction, it is easier to source "driving in neutral" than "driving with the engine turned off." I really like saving fuel, but I dont like when people say wikipedia is not reliable. This happens when editors slack off and are not serious about their sources. Hence, we both can know something, but we still need to source it. Thats all I am saying, just abide to WP:RS and WP:OR. I will try to find a serious website that discusses the dangers of this, and if everything is credible, I think it should be fine. Brusegadi (talk) 21:23, 29 March 2008 (UTC)

Brusegadi, One or more of the references for Wyane Gerdes says that he does "auto-stop" maneuvers (i.e. with the engine off). WP:SYN#Sources says to "stick to the sources". --Mikiemike (talk) 19:24, 30 March 2008 (UTC)

Yes, and that is not a good source for the technique in general, it is a good source for Gerdes liking that stuff thought. This is not mainstream, as your unability to find a good source demonstrates, so it is getting undue weight compared to more mainstream practices. Brusegadi (talk) 19:31, 30 March 2008 (UTC)

I think you both have good points here. I think the best solution is to include some of this material, carefully edited, rather than stripping it out completely or including it all. This is not the place for a long, rambling collection of all the ideas anyone has had about this stuff. A more extended discussion, with more of a how-to focus might be appropriate in wikibooks, and could be linked from here. In approaching a compromise through multiple edits, we may improve the quality of the writing, as well as reaching a good balance as far as what material is included.Ccrrccrr (talk) 13:10, 29 March 2008 (UTC)

Crrccrr, I agree. However, the article isn't that long yet, even to be a complete article, let alone a book. Anyway, organization matters more than length. A longer organized article is better than a shorter unorganized article. The issue is, can the reader quickly find the info they're looking for. IMHO, the safety issues of driving in neutral qualifies as an FAQ. So IMHO a section on this is appropriate. I think it's so ironic that you guys want to delete the safety section due to reasons of safety. Ironically the very reason why you guys want to delete it is the reason why it's an important and relevant issue. Anyway, there are credible references that professionals like Wyane Gerdes use these controversial maneuvers, and this makes it "established", and not WP:Fringe, despite Brusegadi's claims. Maybe you guys should find some valid sources to back up your claims that these maneuvers are unsafe, rather than just deleting sourced info based on your suspicions. Deleting sourced material is like "reverse-vandalism".
--Mikiemike (talk) 18:35, 29 March 2008 (UTC)

Additions to "Fuel economy-maximizing behaviors" article

Dear editors, we are trying to source all the material for this article, because the topics are controversial. Please include sources or else unreferenced additions may be deleted. Thanks, --Mikiemike (talk) 20:46, 12 April 2008 (UTC)

Actually, I tried to post the source of my recent addition to the article on "drafting", but for some reason Misplaced Pages won't allow the site to be posted as a reference, I get a message that the site has been "blacklisted". I cannot even post the URL here, but it is one of the articles at "omninerd dot com". Can anyone shed some light about what is going on here? SONORAMA (talk) 09:58, 13 April 2008 (UTC)

Deleted unsourced "Drafting or tailgating" section by User:SONORAMA 15:55, April 12, 2008

I just removed the following material. It sorta sounds good, but it is unsourced. Due to the controversial subject, the defacto policy is to delete all unsourced material. (I had to put up with it, so everyone else does too.) User was warned above and on their talk page.

User:SONORAMA 15:55, April 12, 2008 wrote:

";Drafting or tailgating. Following a large vehicle such as a semi-tractor trailer on the highway will increase fuel mileage due to the reduction of air resistance. However, this is only accomplished with great risk. Should the truck suddenly apply the brakes, a rear-end collision could ensue. Furthermore, any savings in gas mileage would likely be spent on repairing windshield damage from stones or other debris kicked up by the truck. The drafting driver's visibility is also greatly diminished, thus the driver is unable to avoid small road obstacles such as tire re-treadings."

--Mikiemike (talk) 02:52, 26 April 2008 (UTC)

Removed unsourced material

I just removed this passage:

"Coasting in neutral removes one control drivers might otherwise use to avoid accidents: acceleration; leaving only braking and steering controls. Thus, advocates of coasting may discount the likelihood that acceleration (lost when coasting in neutral) is critical for avoiding most accident scenarios."

At first the language confused me. After re-reading it I understood it, but this subject is so hyper-controversial, and so difficult to keep neutral. We really need references.

I agree that "Coasting in neutral reduces the driver's control of the vehicle to an extent." However, it is controversial and uncertain whether drivers might otherwise use acceleration to avoid accidents, and whether this is more safe than using only braking and steering controls. I somewhat agree that "advocates of coasting may discount the likelihood that acceleration (lost when coasting in neutral) is critical for avoiding most accident scenarios."; however it is equally valid to say that "critics of coasting may overstate the significance or importance of acceleration for avoiding accident scenarios.". Neither statement is really neutral. Anyway, Misplaced Pages technically requires everything to be referenced. Neither of these statements is supported with references. --Mikiemike (talk) 07:30, 1 May 2008 (UTC)

I don't think it is controversial, as such. Nobody who understands the implications would deny that coasting in neutral is somewhat less safe than being in gear, and either are preferable to switching the engine off. Whilst this may be inconvenient to someone's argument, I doubt you will find any rational person who claims different. If some enthusiasts believe that the increased risk is justified by the fuel consumption saving, you may be able to find quotes supporting that. I doubt they will be WP:RS. The reasons why coasting in neutral is less safe is not just that the option of accelerating out of trouble is removed. That's actually less important than some other reasons. I'll have another look through this appalling article and see if it bears some weeding.Greg Locock (talk) 08:50, 1 May 2008 (UTC)

There has been a history of additions and reverts on this topic, and much discussion, and by definition that proves it is controversial.

You wrote: "Nobody who understands the implications would deny...". I disagree with that reasoning. You don't speak for everyone, and you don't speak for me. I have a different POV. We need to acknowledge and respect each other's POV. Misplaced Pages policy includes: WP:NPOV, WP:RS. Any unreferenced content can be removed, period. Referenced content should not be removed until it is discussed, and the dispute is resolved. There are multiple points of view on this subject, and they all should be represented in the article. Just because you don't agree with some of the content is not a valid reason to remove referenced content, because this content may represent a POV other than your own. I assure you that these behaviors, while they are controversial, are practiced by recognized and celebrated practitioners, and there are reliable sources and verifiable sources to support these claims. If you read the article and check the references, I'm sure you will find this is the case. It may seem strange to you, but WP says that verifiability is more important than "truth". "Truth" is subjective, but verifiability is objective. There is a certain truth in verifiability. Misplaced Pages is criticized for allowing anyone to write whatever they want. Verifiable references are the solution to this problem. Also, nothing I know of resolves controversy faster than allowing multiple POV's, and using neutral unbiased language. --Mikiemike (talk) 00:46, 2 May 2008 (UTC)

I suggets that you read what I wrote as opposed to what you seem to think I have written. Greg Locock (talk) 05:31, 2 May 2008 (UTC)

First para crit

"Fuel economy-maximizing behaviors describe techniques that drivers can use to optimize their automobile fuel economy. The energy in fuel consumed in driving is lost in many ways, including engine inefficiency, aerodynamic drag, rolling friction, potential energy required to climb hills, and kinetic energy lost to braking (absent regenerative braking). Driver behavior can influence all of these."

So, these cars climb hills, but never descend them. Somehow the driver can choose not to ascend hills, what does he do, build a tunnel? Bit tough if he lives at the top of the hill.

"The city mileage of conventional cars is much lower than highway mileage due to: 1) a high proportion of idling time, 2) operation mostly at very inefficient low-output engine operating points, and 3) more frequent braking." eg Nissan sentra auto 29 mpg city 36 highway. Is that really MUCH lower?

Greg Locock (talk) 09:49, 1 May 2008 (UTC)

Potential energy from climbing hills is recovered when decending. see conservative force. Any car that ascends a hill will eventually descend.

29 mpg is 20% lower than 36. This is significant, especially with climate change being what it is, and when most vehicles run on non-renewable fuels. Also prices are at record levels. It is significant difference when a hybrid vehicle or electric vehicle can get 50 to 100 mpg city.

--Mikiemike (talk) 00:46, 2 May 2008 (UTC)

way to go missing the point again. Ah well, I shall enjoy editing this article. Greg Locock (talk) 05:32, 2 May 2008 (UTC)

Fuel Economy infobox

In a related matter, does anyone think that fuel economy should be kept out of the automobile infoboxes? Please voice your opinion at http://en.wikipedia.org/Template_talk:Infobox_Automobile#Vote_on_Fuel_Economy_in_the_Infobox 198.151.13.8 (talk) 18:28, 7 May 2008 (UTC)

1. http://en.wikipedia.org/User_talk:Mikiemike#Safe_driving