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Considering removing the windshield wipers...

Discussion in 'Gen 3 Prius Fuel Economy' started by TrailRider, Mar 15, 2011.

  1. mad-dog-one

    mad-dog-one Prius Enthusiast

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    With a dirty windshield, can you see the difference from inside the car? Windshield wipers aren't a fashion statement, they are functional safety equipment intended to make it easier to see out of the front window.
     
  2. rrolff

    rrolff Prius Surgeon

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    I'm glad you don't "think it matters". I suggest using science for good - and not evil...

    It matters - if someone wants to get better mileage - why would you care?

    As an aside, the use of a raw (not a tasty twice baked) potato, cut in half, then rubbed on the front / rear window has the effect of a water 'wetter' - the drops in a rainstorm fly off - eliminating the need for window wipers.

    You can both save gas, and stay safe at the same time!
     
  3. spiderman

    spiderman wretched

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    ^ kind of like Rain-x? Not to mention you could then cook them up for fries.
     
  4. xs650

    xs650 Senior Member

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    When my Lab would rub her nose on the windshield, it wouldn't fog up where she had rubbed her nose. She probably wouldn't have been up to doing the entire wiondshield though.
     
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  5. The Electric Me

    The Electric Me Go Speed Go!

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    Ultimately, I champion personal freedom. But not at the potential cost of safety.

    I'm pretty sure Toyota factored in the windshield wipers cost in relationship to MPG's in designing the Prius. As much sacrifice and design that HAS gone into making it an efficient vehicle, I hardly think they would gloss over something like windshield wipers IF it made anywhere near a big difference. Science or no science, study or no study, I cannot believe that for the average daily driver it makes a significant difference.

    Visibility and safety are important. Windshield wipers...wipe windshields...and thus are important.

    If you want to go forth -rubbing a potato on your windshield as a replacement for using a windshield wiper? More power to ya! But yeah, I think the whole idea of abandoning windshield wipers for asthetics or MPG "savings"...stupid.

    If you were ever in wreck...that resulted in any amount of damage, I certainly wouldn't want to explain to my insurance company why I was driving in Potato Mode...and had removed my safety equipment in the form of windshield wipers.
     
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  6. GSW

    GSW PRIUS POWER

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    My REAR windshield wiper removal was a fashion statement. It was also a "I want to have an unblocked rearview statement". With the headrests down on the rear seats its really a great unobstructed view.
     
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  7. rrolff

    rrolff Prius Surgeon

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    Here we go again with the "I'm pretty sure's" - sounds more like an educated guess (at best). Did you talk with any designers at Toyota?


    Visibility and safety are important. Bees make tasty honey which bears like... and thus are important (logic please???)

    You may think saving gas is stupid - I think it's very environmentally sound. We should all strive to use *less* of our planets valuable resources. I commend all the people who have used science to help our community. Getting 15MPG more may not mean anything to you - but it does to many in these forums.

    If you are mocking the use of potatoes ("Potato Mode") - you are only showing your ignorance. Have you ever tried it? As a previous poster pointed out, the potato could also be re-used (I would clean the window before applying the Potato)...

    Striving to be green is a good thing - and Facts are Facts.
     
  8. The Electric Me

    The Electric Me Go Speed Go!

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    Would any of us be here if we didn't appreciate being green and saving resources? It kinda goes hand in hand with even being part of Prius Chat.

    Yes, I'm guessing about the actual scientific, quantifiable MPG gains made with or without windshield wipers...BUT like I said, It's SAFETY EQUIPMENT...so whatever gnats nice person gain it IS or Isn't, I'd easily side with paying it...

    Also I think it is a good educated guess that with Prius there probably isn't a huge difference. Why do I make this guess? Because Toyota in their own advertising HERALDS the amount of hours the Prius spent in the wind tunnel, and they Herald the low drag of the vehicle.

    Given the entire body design, underbody plating, and fender design...I DO BELIEVE that if windshield wipers could be adapted to make a BIG difference..Toyota would of done it. I don't think a Prius with Windshield Wipers is going to be significantly less efficient than a Prius without Windshield Wipers. However, I do believe a Prius without windshield wipers could be significantly less safe.
     
  9. rrolff

    rrolff Prius Surgeon

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    You are welcome to your own opinions - however twisted they may be.

    There is a good chance we will get time this weekend in the JPL wind tunnel (rumor is we can get in late Saturday/early Sunday). We already have 3 brands of wipers purchased for the tests (thanks to those who volunteer their time to the common good - you know who you are)...

    I'm re-installing the eye bolt on my car's roof. Yes - we did this before - the center main cross beam holds the whole weight of the Prius - it allows testing without road resistance (car suspended). The car is silver, so the large bolt is relatively unobtrusive. I never should've removed it (I have a silver 'plug' for the whole) - it comes in handy for oil changes etc (never really tried it)...

    We will have a very good set of data to backup previous tests. Facts are Facts. Getting 20% better mileage is not only environmentally sound, it saves big $$$ - and with gas over $4 (here in CA), that pays for lunch each day I drive it...
     
  10. The Electric Me

    The Electric Me Go Speed Go!

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    I would say my opinions...are no more twisted than yours. I appreciate efficiency...it's a big part of my support and following of Prius and involvement in Prius Chat.

    However, I have to take Toyota at their word. We already know as fact that "as is" The Prius is the lowest drag coefficient commercially available vehicle you can purchase.

    Also, I think I can present as fact, that windshields get dirty and dirt or rain impedes visibilty...which can be dangerous. Niffty Rain-X, Potato trick aside? I think the idea that people would routinely rub a tuber over their windshields in a valiant hope that it precludes need to use a windshield wiper- realistic folley.

    And seriously, I think windshield wipers are considered standard safety equipment. I do think you could be taking legal risk if you removed them and found yourself in any accident where lack of visibilty could be sited as cause for damage.

    Good luck being as efficient and green as you "safely" can be. I applaud the effort. But I think for the GREATEST majority? Windshield Wipers are simply a necessary and valid piece of equipment.

    Since almost every single vehicle produced and sold comes with them? I'd almost present it as fact.

    PS.

    I have nothing against testing and improving design. Some vehicles have wipers that are recessed underneath the hood itself...until they are activated...

    If it could be proven that a tweak in hood design or wiper placement could make an improvement? I have no qualms or issues in making that improvement.

    But I do have qualms with removing basic safety equipment from a vehicle...even if you believe the "savings" could buy you lunch...
     
  11. GWhizzer

    GWhizzer not so Senior Member

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    Whoa now, hold the phone, doesn't this by definition invalidate the test since aerodynamic characteristics will be different without the close presence of the road - as any pilot familiar with "ground effect" could attest to?
     
  12. rrolff

    rrolff Prius Surgeon

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    Wipers are fitted due to regulatory requirements for automotive sales/safety.

    In the EU, Directive 78/318/EEC - Automotive - Enterprise and Industry is the actual directive. This is a requirement for automotive type-approval in the EU.

    For the US, FMVSS 104 covers the similar requirement http://www.nhtsa.gov/DOT/NHTSA/Vehicle Safety/Test Procedures/Associated Files/TP-104-08.pdf

    While it is clear wipers are required as part of the 'whole vehicle approval', this has nothing to do with vehicle operation after a car is sold.

    If people want to save 3.14% by removing their wipers, that translates to huge$ in the long run (note we haven't tested different wipers yet). The more people saving gas, the less our country relies on foreign oil.

    You should be applauding our efforts - taking a stock Gen III Prius, and applying all the mods, it may be realistic to turn a 50MPG car into a 70MPG car (without the plug-in hassles).

    My 44.5MPG daily driver is now running 58.3 thanks to flaps and the like. I've been running without wipers for a few days - but I'll leave it to the lab to show the actual savings...
     
  13. nerfer

    nerfer A young senior member

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    Just so that this doesn't get repeated as fact later on, my statistic that "68.5% of all statistics are made up" was indeed made up (I was paraphrasing Homer Simpson if I recall correctly). I thought that statement was obvious as tongue-in-cheek, but now I'm not so sure.

    I read some of the following thread, but the main thing I noticed was that nobody has posted any links to a study on windshield wiper aerodynamics. Since it seems most people find rolff's statements hard to believe, the burden of proof would fall upon him. I know fully well how search engines work, but why should I spend time looking for something that I doubt exists? He could have cut this whole thread short by providing proof on the first request and saved himself quite a bit of time and stress in typing responses.

    I did however do a real quick search, and the first relevant link provided this quote:
    Not sure I believe that either, we're still missing actual data. Is this the Insight I or II? What is the considered the 'front end', what is the effect on Cd? For cars in general, it depends if the wipers are tucked into that little space between the hood and the windshield (in which case they probably do help) or if they are exposed (probably add drag).

    If you were able to permantly remove the wipers and close the gap between the windshield and hood, that would undoubtedly be the best situation, aerodynamically. But cars need wipers, just like they need some way of providing a rear view, which at this point still requires outside mirrors poking into the windstream (small camera lens outside and inside monitor would be significantly better).
     
  14. rrolff

    rrolff Prius Surgeon

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    The tests are meant to only reflect actual drag. They have large computers that then model this data as it works in the real world.

    This is how we showed how much lateral stability (along with improved mileage) is added when the Shark Fin antenna is fitted in place of the stock antenna.
     
  15. The Electric Me

    The Electric Me Go Speed Go!

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    I do respect your efforts.

    But what it boils down to is the Original OP's situation. "Considering" removing windshield wipers.

    I respect efforts to be more "green". But I think there are important, real and tangible reasons we have windshield wipers on vehicles, that IMO supercede any gas mileage savings...

    Basically, you can throw any advantage, any savings right out the window if you are involved in an accident because dust or dirt impeded your vision and you didn't have the option of clearing your windshield.

    In all this debate...outside of recommending Mr. Potato Head as a replacement...you totally ignore the reality that windshield wipers provide an important function to safe automobile operation.

    I applaud. Test...improve....

    But I cannot recommend that anyone seriously consider windshield wiper removal at the cost of safety or even for the benefit gas mileage improvement.
     
  16. nerfer

    nerfer A young senior member

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    Wait a minute:
    So are you saying removing the wipers lowers your mileage or improves it? One of these posts must be incorrect.

    I might test the potato idea. Cheaper than rain-x.
     
  17. rrolff

    rrolff Prius Surgeon

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    Where in the world are you getting your statistic "most people find my statements hard to believe". There are almost 1300 instances where this thread was read. "Most people" - I don't think so... I believe there are a few narrow minded people posting in this thread - that's just my opinion.
    You can either search or not - I know the facts. After this weekend's tests, we will have further proof (one way or the other - I am keeping an open mind).
    Interesting I also did a search on drag and wipers, and came up with
    "
    [ame="http://www.google.com/search?hl=en&client=firefox-a&hs=FpI&rls=org.mozilla:en-US:eek:fficial&q=inauthor:%22New+York+Times%22&sa=X&ei=YlOCTb2EOYi2sAP-0NiDAg&ved=0CFoQ9Ag"]New York Times[/ame] - 2001 - Music - 496 pages
    Now It Can Be Lip-Synched," Mr. Epperson was never a classic drag queen, ... her eyes moving like windshield wipers, her mouth alternately a shark's smile ...
    books.google.com/books?isbn=0815333412..."

    What does that prove?


    Your posts are not portraying you in a very good light. I suggest keeping an open mind. I'm off to lunch for some shepherds pie (Happy St Pats to all).
     
  18. hyo silver

    hyo silver Awaaaaay

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    Does the Prius fit in the windtunnel sideways? Maybe you can provide some fixes for the sensitivity to crosswinds. Plus, answer the eternal question of whether 'tis slipperier in the wind, the windows to be up or not be up. :p
     
  19. rrolff

    rrolff Prius Surgeon

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    I have not ignored safety. To the contrary, I have posted very good reference *facts* regarding wipers (US and EU safety regulations regarding new vehicle approval - complete with the whole regulation and associated tests that wipers/cars must pass).

    The use of a Potato (your attempt and Potato humor fails me) is very relative to driving safety. BTW - even *if* you leave your wipers on, it helps with visibility. Try it some time.

    I'm sure we will not be able to use water in the wind tunnel (setup issues), but if it is possible, I will post pics showing how safe driving can be.
     
  20. rrolff

    rrolff Prius Surgeon

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    You are correct. 3.14% was the increase in mileage (better performance).