tire size
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tire size
Hello all, I have a 2005 fx4 extcab 5.4, it has 265 70 r17 tires stock, I want to go 285 70 r17, anyone know how much my speedo will be off, the 5.4 is no power house, will the trans down shift more by throwing the ratio off this much, it doesn't seem like much to me but maybe someone here had experience before I order tires, and I am planning on mounting Kenda Kliever MT's 10ply. thank you!
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A 265/70R17 is 265 / 25.4 * .7 * 2 + 17 = 31.606 inches tall.
A 285/70R17 is 285 / 25.4 * .7 * 2 +17 = 32.709 inches tall.
The 285 will be 3.5% taller.
Now, there is a difference between all tires, some brands will run slighter smaller or larger given the same size. If you can compare the tire diameters from the manufacture that will be more accurate. But 3.5% is approximately where you'll be at. At 30mph that's 1mph off, at 60 that's 2mph off. Not a big deal. A taller tire effectively changes your overall gearing. At the same speed you will be running slightly lower engine rpms.
A 285/70R17 is 285 / 25.4 * .7 * 2 +17 = 32.709 inches tall.
The 285 will be 3.5% taller.
Now, there is a difference between all tires, some brands will run slighter smaller or larger given the same size. If you can compare the tire diameters from the manufacture that will be more accurate. But 3.5% is approximately where you'll be at. At 30mph that's 1mph off, at 60 that's 2mph off. Not a big deal. A taller tire effectively changes your overall gearing. At the same speed you will be running slightly lower engine rpms.
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Hello all, I have a 2005 fx4 extcab 5.4, it has 265 70 r17 tires stock, I want to go 285 70 r17, anyone know how much my speedo will be off, the 5.4 is no power house, will the trans down shift more by throwing the ratio off this much, it doesn't seem like much to me but maybe someone here had experience before I order tires, and I am planning on mounting Kenda Kliever MT's 10ply. thank you!
https://tiresize.com/calculator/
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