Brakes Wheels 1st Gen Tires Corrected Speedo inaccuracys

Discussion in '1st Generation: 2002–06 R50, R53 & 2004–08 R52' started by docv, Nov 14, 2010.

  1. docv

    docv Well-Known Member
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    Aug 30, 2009
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    I put a different set of wheels and tires on my MINI and the speedo is now dead on. Like everyone else the speedo was 4 or 5 MPH off, I removed a set of 15" 175/65 R15's and replaced with a set of 16" s-lites with 205/55 R16's and that corrected the error. 70 MPH is confirmed with the Garmin the same up and down the dial.
     
  2. lotsie

    lotsie Club Coordinator

    May 5, 2009
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    Great!!! Now you can confirm your speeding.

    Mark
     
  3. Metalman

    Metalman Well-Known Member
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    I cross referenced it. So it looks like a tire diameter of 24.9" is the sweet spot for accurate speedo readings. Tires not trunks.:D
     
  4. lotsie

    lotsie Club Coordinator

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    I was 14 the last time I fit a 24:lol:

    Mark
     
  5. Justa Jim

    Justa Jim Well-Known Member
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    Tried that and Docv is right in it correcting the speedo. It also killed acceleration and mpg, on my justa, due to extra weight, so I went back. Have you noticed a change in these two things since you put the larger tires on?

    Jim
     
  6. docv

    docv Well-Known Member
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    Havent noticed much yet, just put them on Friday. I can tell it sticks the corners better, the tires I put on are Goodrich G-Force. Wont get to check out MPG for a week or so.
     
  7. Justa Jim

    Justa Jim Well-Known Member
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    I just realized that you and Lotise have R50's and I have an R56. The gearing might be different enough to make them react completely opposite.

    Jim
     
  8. lotsie

    lotsie Club Coordinator

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    I'm quicker on a smaller overall tire size. Smaller as in less tall.

    Mark
     
  9. docv

    docv Well-Known Member
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    The gearing is strange on the R50, it the only car I have ever owned that you can drive 35 or 40 in any gear, and it has always felt like it needs that sixth gear.
     
  10. Justa Jim

    Justa Jim Well-Known Member
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    Interesting. I have that sixth gear and I lost a lot on a larger tire.

    Jim
     
  11. goaljnky

    goaljnky New Member

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    I am still 24. But I have to measure my thigh to get that.
     
  12. BThayer23

    BThayer23 Well-Known Member

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    The wider tire will affect your MPG, too, beyond just the gearing differences - more rolling resistance.
     
  13. Justa Jim

    Justa Jim Well-Known Member
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    Yepper, I found that out. :frown5:

    Jim
     
  14. Angib

    Angib New Member

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    I went back to 15s from 16s last week (for my first ever drive on winter tyres, which just aren't used in Britain). The first thing I noticed was just how much livelier the car is, particularly on acceleration from a standstill.

    I have trouble believing that I could feel the difference in a 2% change of gearing - but then I don't think the 30% reduction in wheel weight is all that significant either. so I can't explain what I feel.
     
  15. Justa Jim

    Justa Jim Well-Known Member
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    I can't tell what type MINI you have, but mine is a R56 and the weight made a real difference. I plan to go to lighter wheels too, as I think that will also be a help. Second generation justa's are not like the MCS, but can be made more responsive in in different ways. I am back to the stock size, but the Yokohama tires I got handle very nicely in the turns.

    Jim
     
  16. Rooster

    Rooster New Member

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  17. Justa Jim

    Justa Jim Well-Known Member
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    Get a Scan Gauge. The MPH readout is adjustable.

    Jim
     
  18. BThayer23

    BThayer23 Well-Known Member

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    I had a shop calibrate my speedo a few years ago. I'm not sure what's involved mechanically, but it got me out of a speeding ticket. :D
     

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