1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Changing tire size

Discussion in 'Gen 3 Prius Fuel Economy' started by Kimoy, Sep 29, 2012.

  1. Kimoy

    Kimoy Member

    Joined:
    Apr 1, 2010
    168
    24
    0
    Location:
    Chicagoland
    Vehicle:
    2010 Prius
    Model:
    III
    My original Yokohama avid s33 is about ready to be changed. It now have over 42k on them. I think I can still stretch it before the winter starts. My OEM size are 195/65/15 and I'm thinking of getting the 205/65/15. According to Tire Dimensions Made Simple - Discount Tire my tire rotation will decrease by over 16 revs per mile. I know the side wall is going to be about a quarter an inch higher about an inch and a half bigger in circumference And the car is going to sit half an inch higher and a wider Witdh.
    Have anyone done this to their Prius and what are your observation/s pertaining to performance, mpg, handling, traction, etc.
     
  2. Kimoy

    Kimoy Member

    Joined:
    Apr 1, 2010
    168
    24
    0
    Location:
    Chicagoland
    Vehicle:
    2010 Prius
    Model:
    III
    And one more thing, what tire do you recommend and why?
     
  3. F8L

    F8L Protecting Habitat & AG Lands

    Joined:
    Aug 14, 2006
    19,011
    4,080
    50
    Location:
    Grass Valley, CA.
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    Why do you want a taller tire?
     
  4. Kimoy

    Kimoy Member

    Joined:
    Apr 1, 2010
    168
    24
    0
    Location:
    Chicagoland
    Vehicle:
    2010 Prius
    Model:
    III
    Should I go 205/60/15?
     
  5. F8L

    F8L Protecting Habitat & AG Lands

    Joined:
    Aug 14, 2006
    19,011
    4,080
    50
    Location:
    Grass Valley, CA.
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    I can't suggest anything without knowing your motives. If you need ground clearance then the 205/65/15 will give it to you. If you want better handling then the 205/60/15 will give it to you. Either one will change your speedometer reading.
     
  6. a priori

    a priori Canonus Curiosus

    Joined:
    Aug 14, 2007
    3,083
    407
    23
    Location:
    Chicagoland (West)
    Vehicle:
    2010 Prius
    Model:
    V
    . . . and, more likely than not, lower your fuel economy.
     
  7. Kimoy

    Kimoy Member

    Joined:
    Apr 1, 2010
    168
    24
    0
    Location:
    Chicagoland
    Vehicle:
    2010 Prius
    Model:
    III
    I'm trying to get the best mileage and handling out of my tire. Looking at the discount tire's web site your actual speed changes as you change your tire size so I was assuming that it might correct the 2mpg discrepancy on the actual and speedometer mpg if I change it. Or does your speed have nothing to do with your mpg?
     
  8. F8L

    F8L Protecting Habitat & AG Lands

    Joined:
    Aug 14, 2006
    19,011
    4,080
    50
    Location:
    Grass Valley, CA.
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    Speed has everything to do with your fuel economy but if you change your tire size to a larger tire to fix the 2mph speedo error then you will start driving 2mph faster than you used to which will result in lower fuel economy. That is if you continue to just set your cruise control for 65mph. :)

    I found it very difficult to drive at 58mph instead of 60mph after installing larger tires. I knew that, with my OE tires, I was really driving at 58mph when the speedo read 60mph but that was ok. After going to larger tires I just couldn't bring myself to drive with the speedo reading 58mph. Physiological thing I guess. :)
     
  9. Kimoy

    Kimoy Member

    Joined:
    Apr 1, 2010
    168
    24
    0
    Location:
    Chicagoland
    Vehicle:
    2010 Prius
    Model:
    III
    Just bought a 16 inch rims that came off a Prius V and now wondering what size tire should I buy.
    205/55? 205/60? What do you guys suggest for best mileage and handling.
     
  10. F8L

    F8L Protecting Habitat & AG Lands

    Joined:
    Aug 14, 2006
    19,011
    4,080
    50
    Location:
    Grass Valley, CA.
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    The Prius v has a different bolt pattern than the Liftback!
     
  11. camry25

    camry25 Junior Member

    Joined:
    Nov 20, 2009
    46
    2
    0
    Location:
    l.a.
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    PriusV offset is the exact same?
    As long as width is same mileage won't b affected
     
  12. Mr Incredible

    Mr Incredible Chance favors the prepared mind.

    Joined:
    Jun 23, 2008
    955
    506
    0
    Location:
    Neb
    Vehicle:
    2012 Prius c
    Model:
    Four
    Mileage is a different target than handling. If you optimize one it likely won't optimize the other.

    Choose which one you prefer and buy tires for that. Then tell us what you find.

    It's all your choice.
     
  13. Britprius

    Britprius Senior Member

    Joined:
    Jun 14, 2010
    5,194
    1,910
    0
    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    I have gone from 195/55/16 tyres on my UK Prius too 205/55/16 the speedo is more accurate but still over reads by about 2 mph. Handling has greatly improved and with careful choice of tyres my mpg has gone up by about 3 mpg over the OEM tyres. The oddo now under reads by 2.8% but the MFD mpg now shows almost exactly the same as calculated MPG when I add the 2.8% extra miles (covered but not recorded) in the calculation.
     
  14. Kimoy

    Kimoy Member

    Joined:
    Apr 1, 2010
    168
    24
    0
    Location:
    Chicagoland
    Vehicle:
    2010 Prius
    Model:
    III
    Isn't the ct200h the same as the Prius V wagon?
     
  15. F8L

    F8L Protecting Habitat & AG Lands

    Joined:
    Aug 14, 2006
    19,011
    4,080
    50
    Location:
    Grass Valley, CA.
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    No. The CT200h unlike the rest of the nice Lexus cars, uses a 5x100 bolt pattern whereas the Prius v wagon uses a 5x114.3 bolt pattern.

    The GenII and GenIII Prius use a 5x100 bolt pattern. The CT200h wheels are similar yet quite different than the Prius v wheels.
     
  16. terpsmandan

    terpsmandan Member

    Joined:
    Sep 26, 2012
    143
    13
    0
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    According to my GPS, my speedometer reads about 2 mph low. Going up in diameter will correct that. On my 05 Wrangler, with the OEM 30" tires (29.5 acutal) my speedo read low and I put on 31's (30.5 actual) and my speedo is right on to my GPS in my phone.
     
  17. 2010_Prius_I_White

    2010_Prius_I_White Junior Member

    Joined:
    Aug 8, 2012
    62
    14
    0
    Location:
    Las Vegas, NV
    Vehicle:
    2010 Prius
    Model:
    I
    I know this might sound like a dumb question, but how does making a tire wider help fix the odo misread? Wouldn't you have to make the diameter larger to help that? Or am I just not getting somethin. Because that's totally possible. lol
     
    kenoarto likes this.
  18. a priori

    a priori Canonus Curiosus

    Joined:
    Aug 14, 2007
    3,083
    407
    23
    Location:
    Chicagoland (West)
    Vehicle:
    2010 Prius
    Model:
    V
    I think the wideness of the tire is almost a happenstance, here, but you would expect larger diameter tires (with shallower sidewalls) to have wider treads. The more critical point is the revolutions per mile (essentially a circumference measurement).
     
  19. 2010_Prius_I_White

    2010_Prius_I_White Junior Member

    Joined:
    Aug 8, 2012
    62
    14
    0
    Location:
    Las Vegas, NV
    Vehicle:
    2010 Prius
    Model:
    I
    I was trying to get some new rims and tires, but I was't really sure what's best or how to weigh out comparisons between FE, handling, and looks. . .
     
  20. a priori

    a priori Canonus Curiosus

    Joined:
    Aug 14, 2007
    3,083
    407
    23
    Location:
    Chicagoland (West)
    Vehicle:
    2010 Prius
    Model:
    V
    I think you've already figured out that F8L has done a good bit of research on this question. The first thing he'll ask you is this: Why are you looking to make a change -- what is it that you don't like and/or want to accomplish by making a change? Your answer(s) will guide the whole process. If you are looking simply for higher fuel economy, you'll find that the best thing to do is keep the 15" wheels and get Michelin Energy Saver AS tires. Beyond that, the answers will vary considerably depending on what you are seeking.
     
    2010_Prius_I_White and F8L like this.