Speedo: How off with 33s?

Discussion in '100-Series Cruisers' started by macneill, Nov 1, 2005.

  1. macneill

    macneill Rollin’ on 33s

    Messages:
    4,062
    Likes Received:
    9
    Joined:
    Jun 2, 2004
    Location:
    Port Washington, NY / Edgartown, MA
    What is difference in mph with 33s?

    Not that Grandpa here rarely goes above what I think is 65, but was just wondering how off it is.
     
  2. spressomon

    spressomon glutton Moderator

    Messages:
    12,544
    Media:
    13
    Albums:
    1
    Likes Received:
    1,143
    Joined:
    Jan 9, 2005
    Location:
    Northern Nevada
    Mac,
    With my 285R75 16 GY MT/R's the actual difference (GPS) is 5%. So at 65mph the actual speed is 68mph (actually 68.25).
     
  3. macneill

    macneill Rollin’ on 33s

    Messages:
    4,062
    Likes Received:
    9
    Joined:
    Jun 2, 2004
    Location:
    Port Washington, NY / Edgartown, MA
    Ahhh... very good. Thanks.
     
  4. mheredia2930

    mheredia2930

    Messages:
    14
    Likes Received:
    0
    Joined:
    Apr 2, 2005
    Location:
    Los Angeles, CA
    I had mine checked a few years back, but I remember that there was a 12-13% difference with my FJ60. I have 33x12.5x15. So when it shows 65mph on my speedometer, I am actually going about 75mph... Hope this helps..
     
  5. hoser

    hoser SILVER Star

    Messages:
    8,888
    Likes Received:
    1,142
    Joined:
    Dec 21, 2003
    Location:
    Bay Area, CA
    If one didn't have a GPS...

    33"/31.3"=1.05
    A 5% increase given the speedo is accurate in the first place.
     
  6. ShottsUZJ100

    ShottsUZJ100

    Messages:
    8,690
    Albums:
    1
    Likes Received:
    30
    Joined:
    Apr 2, 2003
    Location:
    Tucson, AZ
    33 = 5%
    35 = 12%
     
  7. spressomon

    spressomon glutton Moderator

    Messages:
    12,544
    Media:
    13
    Albums:
    1
    Likes Received:
    1,143
    Joined:
    Jan 9, 2005
    Location:
    Northern Nevada
    Remember "31", "33" etc. is nominal dimension...ultimately the actual circumference may differ slightly for each brand/model of tire.
     
  8. Cruiser_Nerd

    Cruiser_Nerd That 25 Guy. Moderator

    Messages:
    4,254
    Likes Received:
    193
    Joined:
    Dec 3, 2002
    Location:
    Higganum.
    This would make sense, as I think stock tire size on the 60 was a 235/75/15 The 100 would be seeing a smaller difference because of the taller OEM tire. :)
     
  9. tabraha

    tabraha Hello My Name is: TAD SILVER Star

    Messages:
    2,507
    Likes Received:
    632
    Joined:
    Aug 20, 2003
    Location:
    South Carolina
    Pretty much what I get too when I have the 285/75R16 Revo's on.
     
  10. tabraha

    tabraha Hello My Name is: TAD SILVER Star

    Messages:
    2,507
    Likes Received:
    632
    Joined:
    Aug 20, 2003
    Location:
    South Carolina
  11. NMuzj100

    NMuzj100

    Messages:
    3,480
    Likes Received:
    39
    Joined:
    Sep 25, 2004
    Location:
    Gleneagle, CO
    5.4% difference for 285/75R16 vs the 275/70R16 stock tires. YMMV
     
  12. Landpimp

    Landpimp GOLD Star

    Messages:
    15,955
    Media:
    1
    Likes Received:
    1,974
    Joined:
    Mar 14, 2003
    Location:
    Gig Harbor WA
    285's.

    60 on the spedo is 64 on the GPS...............I don't do math :D
     
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.