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All terrain tires

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by Ajwholloway, May 13, 2012.

  1. pmf608

    pmf608 Epic Member 5+ Years 1000 Posts

    People who are saying they have an MPG drop but haven't programmed their speedo, keep in mind that your MPG drop from a larger tire will be exaggerated because your odometer runs from the same sensors as your speedometer and they will be off by the same amount. While a larger tire will lower your MPGs, not reprogramming your speedometer will make it seem like a larger effect because the larger tire also has a larger circumference and you will travel slightly farther for each rotation of the tire. That means your odometer will also report less miles than you are actually travelling when you try to calculate your MPG.
  2. dsfloyd

    dsfloyd Epic Member 5+ Years ROTM Winner Gold Member 1000 Posts

    This is a correct statement.^^^^^^^^

    My examples were with a corrected speedo as well.
  3. TimTom64b

    TimTom64b Member 2 Years 500 Posts ROTM Winner Gold Member

    I have a programmer in my truck... and swapping between stock and 33's changes my mpg an average of 2 mpg. Now just to do a difference in speed testing I had a friend follow running my stock tires when I had speedometer adjusted for the larger and speed difference was 3-5 mph at 45. I didnt test it the other way around as I just wanted to know the difference when I put my winters on and don't adjust the speedometer.
  4. buckmeister2

    buckmeister2 Member 1 Year 100 Posts

    Tim, you only did a "one-up" size change, which has negligible impact on performance or economy. It is the max that is recommended by virtually all tire retailers. You got a better look, and it didn't affect much.

    - - - Updated - - -

    Aj,
    Your stock tire weighs about 39/40 pounds. The tire you will replace it with weighs 57 pounds! So, 17 pounds x4 is 68 additional pounds. Now, that doesn't sound like much, but it is "unsprung" weight, which is not at all like the same amount of weight being put into the back of the truck. Your truck will have to overcome more drag each time you accelerate. The diameter is about a 4% increase, which will likely make your speedometer run about 3 MPH lower than actual, and your odometer will be off by about 2 miles every 100. The speed and odometer errors can be corrected, but the mass/weight will always be there. You will love the way your truck looks, but you may not be too happy with the other changes.
  5. TimTom64b

    TimTom64b Member 2 Years 500 Posts ROTM Winner Gold Member

    I was just sharing my info for just going up 2" in tire size. That amounts to 2 - 3 miles per gallon amounts to almost 50 - 75 miles a tank... or roughly 3 or 4 gallons of gas. That is just with about $13.
  6. donl

    donl Rockstar 100 Posts

    You never stop paying for that oversize rubber. You just can't beat physics.
  7. reggiecab2000

    reggiecab2000 Rockstar 4 Years 500 Posts

    assuming we are talking bout tires of the same width here and tires of the same height, which for time saving purposes, lets say so....
    the 68 additional pounds from a tire of exactly the same size, is EXACTLY the same as 68 additional pounds distributed onto your truck, I get what some people say about this being rotational weight vs. static weight, but realize this, since the tires sit on the ground on a vehicle, if tire size hasnt changed, but weight has increased, then you will have the exact same effect from 68 additional pounds in rubber weight on your rims as you would from static weight in your bed. The only time acceleration, stopping distance, rwhp, etc. changes is when the tire width and/or tire height changes, not weight, unless it is an absurd amount.

    it really is just physics, something ive had too much of in the last few years LOL
    Last edited: May 15, 2013
  8. GrizzlyTN

    GrizzlyTN Rockstar 100 Posts

    I don't have a bunch of math and stats but I can recommend the Toyo Open Country MT's it's more a cross with an AT and the quietist MT I've ever rolled on. I had Nitto Mud Grapplers and they looked great and cut mud like a pro but they were loud as two coons screwin. Yes Toyo's cost more but if you're trying to get the "tough" look and mud capability without the road noise these are what you want.

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