Bigger Tires

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by mowerboy1000, Mar 13, 2007.

  1. mowerboy1000

    mowerboy1000 Member

    I want to get bigger tires on my truck, but I don't want to throw off the speedo and all of that, what will I have to do to adjust for the bigger tires? And does anyone know how big I could go on a 2000 Sierra?
  2. TrailLeadr

    TrailLeadr Epic Member 5+ Years 1000 Posts

    If you get bigger tires, you're going to need to adjust the speedo. There's no way around it. Unless you change the rear diff to compensate for the larger tires.
    It would just be easier to have the speedo re-calibrated.

    Were you asking how big you could go on the '00 Sierra without a lift?
  3. 84fiero123

    84fiero123 Epic Member 5+ Years 1000 Posts Platinum Contributor


    Newer cars and truck no longer have a cable, (Good & Bad). They are electric.

    Someplace on one of my other forum they had a site that will actually help you to calculate what gear you need to change to make the speedo right.

    I will have to look around to find it, unless of course some one here knows it.

    I forget the math, but when you change tires there is a formula to tell you how far off the speedo will be.
  4. mowerboy1000

    mowerboy1000 Member

    Thats right , I don't have a lift, and I don't want my speedo off at all, but I was wondering if there was any way to have the computer reprogramed for the larger tires at a shop or something like that
  5. TrailLeadr

    TrailLeadr Epic Member 5+ Years 1000 Posts

    You should be able to have that done at a shop, but I wouldn't know what the approx charge would be for it.
    Maybe someone else would know.
  6. GWAGON_99

    GWAGON_99 Rockstar 100 Posts

    Here's the deal, I know someone who has 285/75/R17 on the same truck that you drive and has no problems (clearance wise). I have since put 285/70R17 on my '99 Yukon with very little bump on full suspension travel. My speedo is off exactly 6.2%. I simply rely on the math to tell me how fast I am going. I have noticed however that I only calculate it when I see a cop. :biggrin: Now I have read and am pretty sure that the Hypertech Power Programmer will adjust the Speedo if you have changed tire size. You simply plug in your tire size and it automatically adjusts. The PP is about $350-$400 but in addition to an accurate speedo you get improved performance!
    1 person likes this.
  7. mowerboy1000

    mowerboy1000 Member

    I would do something like that, but since it is technically a company truck, I would be worried about doing something like a preformance tuner, but I just hate the way the tires look on the truck now, you can see so much weel well above the tire plus who wouldn't want a little more meat
    1 person likes this.
  8. GWAGON_99

    GWAGON_99 Rockstar 100 Posts

    It may not be as big as you want but you could probably do one size bigger. I think you have the 265's on there now, you could go to a 275 with little effect and it may look a little better.
  9. jimmy-boy

    jimmy-boy New Member

    how big???

    I want to get a set of tires geared more to the off-road side of trucking. What the biggest i can go without a lift on a 2005 1/2 ton Z71. I'm still wanting to use the factory 17" rims...
  10. Cableguy

    Cableguy Epic Member 5+ Years ROTM Winner 1000 Posts

    Jay is right. I've heard Computer will compensate up to 3% after that size its game over. New rolling radius will have to be modified in comp.

Share This Page

Newest Gallery Photos