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Huge loss in fuel economy with wheels

Discussion in 'Gen 2 Prius Fuel Economy' started by tunerPRIUS, May 6, 2013.

  1. fuzzy1

    fuzzy1 Senior Member

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    It is called the 'Edit' button. It won't delete the post, but it can be used to erase all the incriminating content.
     
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  2. wjtracy

    wjtracy Senior Member

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    ???
    Lets say, your normal tire gets 100 miles w/ 2 gals gas = 50 MPG
    Your car reads 60 MPH and is calibrated accurately.

    Now you put on a larger tire say 5% less revs per mile.
    With the larger tire, when you read 60 MPH, you are really going 60 x 1.05 = 63 MPH
    When you calculate MPG you will use still 2 gals gaso but you think you only went 95 miles = 47.5 MPG calc

    So to adjust MPG take 47.5 (obs) x 63/60 = 50 MPG (corrected)
     
  3. tunerPRIUS

    tunerPRIUS Junior Member

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    I am going to run 205-40-18 enkei rpf1 17lbs
    185-65-15 65 mph
    205-40-18 64.97mph

    Doesn't get any closer than that
    Rims are 3lbs lighter than current wheels
    I should get 45mpg and look super sweet doing it too. Here is a photo I found of another Prius w same wheels
    image.jpg
     
  4. tunerPRIUS

    tunerPRIUS Junior Member

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    Update. I had a nail in my tire. Was losing about 5psi a day. I was also running 36-37psi. I pumped em up to 40-42psi. I have only went 100 miles but I get 44.5mpg. In actuality that's 45 w speedo being off a hair. Now the question is...really worth it to lighten up the wheel and run a Eco tire to gain maybe 2-3mpg tops during summer when I run larger wheels
     
  5. F8L

    F8L Protecting Habitat & AG Lands

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    Run a couple of tanks and see how it goes. One trip is not very telling. Shorter trips over the course of a full tank could drop you into the high 30s. If you regularly do longer trips then you may be ok in the low to mid 40s.
     
  6. The Electric Me

    The Electric Me Go Speed Go!

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    Don't want to hijack this thread, but one thing I agree on with the OP is the ugliness of the OEM wheels.

    The Prius for me is about HSD and being efficient. I'm not so much into new rims, wheels or modifications that lower suspension.

    I pretty much like the way The Prius looks driving it right off the dealership lot. But I do have to ask, what was/is Toyota thinking? You have to work to make a wheel cover that looks as ugly as the one that comes standard on Prius. To me the covers look like little Nazi Iron Crosses....and that's NOT a look I want or like.

    And for me, with Sea Glass Pearl, and "black" rims underneath, I don't think removal would be an improvement.

    What I'm eventually going to do about this is a "Back Burner" idea for me at the moment. I'm actually just thinking of getting some cheap generic alternative Wal-Mart wheel covers. IMO the ones they have on the shelf, look a world better than the ones Toyota put on my the Prius.
     
  7. css28

    css28 Senior Member

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    ...and the Walmart wheel covers probably move a lot of air and add drag at high speed.
    What was Toyota thinking? They were reducing drag and improving the high speed fuel mileage.
     
  8. F8L

    F8L Protecting Habitat & AG Lands

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    If you can find someone with 2010-2011 silver wheels who wants to trade for your black wheels you can use your 2013 covers and have a decent looking wheel. Or you can paint your wheels silver.
     

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  9. The Electric Me

    The Electric Me Go Speed Go!

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    That's my fear, and why I say, the whole "project" is a back burner idea at the moment. I realize that the provided wheel covers probably aid somewhat in reducing drag.

    But even being flat, and smooth...do they have to be so damn ugly?

    The Wal-Mart aftermarket covers IMO look nice, and they are cheap. I might be willing to go a $30. experiment and just see how much they impact fuel efficiency.

    A lot of Prius drivers have removed the covers leaving the rims underneath exposed. I'm thinking that action itself removes a lot of any aerodynamic advantage the covers may or may not provide, and I haven't heard a lot of screaming about how the removal of said covers suddenly resulted in a huge plummet in efficiency.

    Trust me, if I slap a set of aftermarket covers on...I'll carefully remove the originals and keep them. If I can't live with any loss of fuel economy I'll put them back. I've spent more money on other failed experiments. And it would certainly be cheaper than buying entirely new rims.
     
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  10. tunerPRIUS

    tunerPRIUS Junior Member

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    Here is my many crucial points IMG_4837.JPG . How many miles a year do you guys actually drive? I drive about 50k miles a year. That being said the money you lose by running a diff wheel cover that looks a million times better is what 1mpg? I am running a 205 series tire and 20.5lb 17" rim and I am losing about 4mpg. When I did the math its like 200$ year give or take with the amount of driving I do. With your driving its prob 25-50$. I would also to mention that a new prius is a total waste of money. 95% of prius owners drive squat for miles and they spend 25-30k on a prius when they could have bought a loaded camry se. To obsess over fuel economy when you drive 10-15k miles a year is just plain pathetic to me. I would rather get 20-25mpg and enjoy driving, get places quicker, pass people quickly or waste a cocky v8 owner with his gf in the passengers seat :) I almost pulled the trigger on these rims cause they are some of the best toyota/subaru oem rims I have seen besides my wrx rims but they also weigh 20.4 lbs. Four 2013 Scion Fr s FRS Factory 17 Wheels Tires Rims Michelin 215 45 17 | eBay

    I could never understand why toyota and subaru make heavy 17s but I already bent one of my rpf1s they are 15lbs it is a strength issue. Larger rim will bend easier than a 15 especially when its thin....In the end i didn't find it worth it to run lighter rpf1 rims unless I run a 15 to 16" rim, I was gonna run 18s but they only make them in 18x8 in 5x100 lug pattern weight 17.4 lbs. That 3lbs would yield me 46.5mpg instead of 45mpg im getting now. Not really worth it. I could run 15s or 16s but then my prius wouldn't look nearly as cool as it does now. Its not easy making a prius which is one of the ugliest cars on the rd look good. Its bad enough we get laughed at for owning one but I like to at least take the time to modify mine and make it unique. We have a large car scene here in Syracuse NY. I have never seen anyone lower a prius even and inch or run larger aftermarket wheels. Prob cause most of the owners are older people who don't give a crap about how their prius looks. You could say they are about maximum mpg? No you are wrong. Most of them drive 10K miles a year (pointless) and the other 5% drive it like a reg vehicle like my friend trisha who gets 40mpg with factory wheels. Now this thread is getting interesting....replies :)
     
  11. tunerPRIUS

    tunerPRIUS Junior Member

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    My friends still wanna pick on me for owning a prius when they drive crappy cars. I tell em oh really you wanna race one of my other cars? My other two vehicles are a 2011 wrx, ported heads, built block, cams, straight cut gears, 2.5xtr turbo, 500whp on e85 and 600+hp at crank. 1996 Eclipse auto GSX. Stock 7bolt, devo2ning built trans, shiftbox, fp3065 turbo, car should make over 600whp 750hp at crank on e85. Both cars get 20mpg on 93oct will do mid 11s on pump gas and hi 10s on ethanol. Basically for people who know race cars. They will take a dump on a 85k vette z06 or skyline gtr twin turbo. I also walk all over 600cc crotchrockets and give old 1000s a run for their money with a 3200lb car haha. My license plate on my prius says IM 2 SLO :)

    IMG_1943.JPG IMG_4515.JPG IMG_0930.jpg
     
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  12. css28

    css28 Senior Member

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    So, where do you drive to put 50k on your car each year? Is it strictly the Thruway or more interesting terrain?
     
  13. dorunron

    dorunron Senior Member

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    Don't get me wrong, if you have the kind of money it sounds like you have, then why are driving a Prius to begin with? :confused:

    I don't want to sound rude, but I just can't make sense out of your actions and your statements. Humor this old man here.
     
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  14. tunerPRIUS

    tunerPRIUS Junior Member

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    I do catering for a company who makes the best sandwhiches/subs in nys. I also delivery blood for another company. I then give drum/guitar lessons. I live about 15 miles from the city. 1/3rd of my driving is to and from work. I think people lack the knowledge and research they should put into a vehicle before they buy it. I did extensive research on the Prius before I bought one. 20 months of driving it and it pays for itself. When u drive 10-20k miles a year, you should purchase something you like and also make a good financial decision. That being said, don't buy a new car especially a Prius. For what a new Prius costs I can get a really nice car that pulls 25-30mpg that has tons of room, doesn't need a special hybrid dealer to work on it. If I want 20mpg I can buy an extremely nice 6 cyl w 250-300hp or a 4 cyl awd turbo car that rips thru snow/rain and kills at the race track. For example. My base wrx is 26-27k new. Ya u spend twice as much in gas but if u drive 10k miles a year u spend jack squat on gas anyways. About 2000-2500$. But u can do 60mph thru the snow and dump the clutch at 5000rpms without spinning. I wanna speak from a sports car owner and hybrid owner. I'm not here insult the Prius it's an amazing vehicle but I just speak the truth. Almost everyone who buys a car for the wrong reasons such as mpg will get bored and trade it in within one year. Being truly happy with a car you love, that spark never goes away
     
  15. F8L

    F8L Protecting Habitat & AG Lands

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    When you get older you'll realize that much of what you feel is important now was either foolish or irrelevant.

    Personally, I think the WRX is hideous and the stereotype of boy-racer that goes with it is worse than owning a Prius. See how opinions work? :)
     
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  16. cwerdna

    cwerdna Senior Member

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    Yep, I've only skimmed some of the OP's latter posts and am puzzled.

    There are many more reasons why someone might own a Prius than about "payback" such as the technology, knowing that some braking energy is being recaptured (and is repurposed) instead of all being wasted as heat and brake dust, putting less $ in the hands of big oil, foreign countries where most of the world's oil resides and terrorists, emitting less CO2, driving a AT-PZEV rated car (so, emitting fewer pollutants), etc.

    What's the "payback" on a BMW, a V8 engine or sunroof? Nothing wrong w/paying for a feature that performs the functions I mentioned. If were all so concerned about "payback", then any car more $12K Versa isn't "worth it".

    I also owned a sports car (287 hp Nissan 350Z) alongside my Prius for many years. It got roughly 1/2 the mileage and required premium. My Prius replaced a 255 hp Nissan Maxima.

    I personally don't care that I'm running w/stock wheels and running on stock sizes. I've never changed the wheels from stock on any of my cars. FWIW, I think it's a waste of money for the OP to be bothering w/the expense of that AND losing mileage. I'd hate to have a set of wheels stolen as well. Heck, when I lived in WA, someone who lived a few blocks away from me had their STOCK 5th gen Maxima wheels stolen. :rolleyes: His car was up on blocks. I don't know the guy, but drove over there to take a look, after he posted about it on maxima.org.

    I don't get why he's so obsessed w/wheel weight when a huge factor is likely his tires are of higher rolling resistance than good LRR tires.
     
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  17. dorunron

    dorunron Senior Member

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    Hmmm. I always thought most folks bought a Prius to save money. And most of those here have sure kept them a lot longer than a year. After reading the above, it makes me think that all the research and study I did over the years was for nothing before we bought ours.

    Oh well, to each his own I reckon.
     
  18. dorunron

    dorunron Senior Member

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    My feelings exactly! Thank you for bringing that up.

    Furthermore, I still think that if the OP would not have made the mod's in the first place, he would not have the reason to be complaining now. IMO, he brought it on himself by his actions.
     
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  19. Sfcyclist

    Sfcyclist Senior Member

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    The direction this thread is going reminds me of this from the very respectable Yo Gabba Gabba.. "get the silly's out, get the silly's out, and that's what its about".... :LOL:

     
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  20. F8L

    F8L Protecting Habitat & AG Lands

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    After awhile you can predict these things. ;)