Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Does this sound right?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by CrazeeBush, Aug 6, 2000.

  1. CrazeeBush

    CrazeeBush 1/2 ton status

    Joined:
    Apr 17, 2000
    Posts:
    464
    Likes Received:
    0
    Location:
    Middle Tennessee
    Have 32x11.50 tires on the k5 and I was trying to figure out the speedo today. I went 5 miles by the mile markers and my odometer showed 4.6 so 1 of my miles would equal 1.086957 real miles, right?

    And here's how I figured my speedo reading so I don't speed horribly.

    5 70mph
    --- = -------
    4.6 speedo value

    With that I got that to do 70 mph I need to do 64 mph.

    Does all this math sound right? Just curious.

    -JoSH
    crazeebush@aol.com
    http://josh.coloradok5.com
     
  2. CrazeeBush

    CrazeeBush 1/2 ton status

    Joined:
    Apr 17, 2000
    Posts:
    464
    Likes Received:
    0
    Location:
    Middle Tennessee
  3. CrazeeBush

    CrazeeBush 1/2 ton status

    Joined:
    Apr 17, 2000
    Posts:
    464
    Likes Received:
    0
    Location:
    Middle Tennessee
  4. jim82

    jim82 Registered Member

    Joined:
    Jun 27, 2000
    Posts:
    71
    Likes Received:
    0
    Location:
    Bay Area
    I think you want to flip one if I remember chem class, you want the labels to cancel out.

    4.6(your miles) X 70miles an hour(real mles)
    -------------- -------------------------- = ?
    5 (real miles) X (your miles)

    i think
    .02
     
  5. jim82

    jim82 Registered Member

    Joined:
    Jun 27, 2000
    Posts:
    71
    Likes Received:
    0
    Location:
    Bay Area
    dude,
    sorry, i dont know if that right, i had a couple earlier, who knows
     
  6. CrazeeBush

    CrazeeBush 1/2 ton status

    Joined:
    Apr 17, 2000
    Posts:
    464
    Likes Received:
    0
    Location:
    Middle Tennessee
    No, them my speedo would read over the speed.... I know it's below b/c I got a ticket =)

    The bigger tire takes longer to make one full rotation so the speedo would reado slower, right?

    -JoSH
    crazeebush@aol.com
    http://josh.coloradok5.com
     
  7. jim82

    jim82 Registered Member

    Joined:
    Jun 27, 2000
    Posts:
    71
    Likes Received:
    0
    Location:
    Bay Area
    right,
    what kinda gears are you running, im running 32 too.
     
  8. CrazeeBush

    CrazeeBush 1/2 ton status

    Joined:
    Apr 17, 2000
    Posts:
    464
    Likes Received:
    0
    Location:
    Middle Tennessee
    honestly I have no clue.. Whatever factory is, 3.08? not sure.. It moves fine considering I have a puny 305 in there.. =( Anwyays, original tire size was smaller than 31", it was P something or other metric crap. If that's the correct math I wanna reduce error percentage and do the calcs after a 50 mile drive and go form there.. I'm too lazy to change the gears.. lol All I need to know is that to do 70 I must do 64 or whatever and that if my speedo shows 85, then I'm going 93 mph.. hehe Not that I've ever done that. **wink wink** "But officer, it only said I was going 85." It tops out with the needle pointg down into the odometer. lol

    -JoSH
    crazeebush@aol.com
    http://josh.coloradok5.com
     
  9. Logan

    Logan Registered Member

    Joined:
    Feb 17, 2000
    Posts:
    93
    Likes Received:
    0
    Location:
    Fournier, Ontario, Canada
    It depends on what size tires you had to begin with. I don't remember what was stock on mine, but I measured them to be 28" tall. I replaced them with 31x10.5's.

    31/28 = 1.11, or about 10% higher. If my speedo shows 100km/h, I'm really doing about 110.

    With your 32's, you're running about 15% over, so if your speed was shown as 60, you'd actually be going about 70. To go 55, you'd want the speedo to read a little below 50.

    Heh, then again, just skip the math -- Have a friend pace you in a car that has stock tires. ;)

    -Al.
     
  10. blazer72

    blazer72 1/2 ton status

    Joined:
    Apr 13, 2000
    Posts:
    939
    Likes Received:
    0
    Location:
    KCMO
    speedo shop told me find the error count the markers and check the aginst the tripmeter or the odometer if you go 20 mile markers and the trip meter says you went 18 then the error is 18/20 * x/100, X is the percent of error. so in this case it 18/20*x/100= 90/100 so the error is 10%.

    THe greater the miles you drive to check the trip to mile marker ratio the the smaller the error.

    I understand the jeep thing I drive a BLAZER!!

    Ken
     

Share This Page