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So as the title says "What does this even mean?"
I am looking at tire company websites and checking out the size tires they have available. and I keep seeing stuff like this 33X12.50R17LT. What the crap is this? Is this bigger or smaller than a 285/70/17? :mecry:
 

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here is the break down: a 33x12.5x17 would be 33" tall 12.5" wide, and fit on a 17" wheel. A 285/70/17 is a metric tire and a little different. The 285 is the width, the 70 is that the side wall of the tire is 70% of the width, and the 17 is again the wheel size. To convert this to an inch measurement is as follows:

Take the 285 (that's milimeters) and divide it by 25.4 that will give you approx. 11.25" That's how wide the tire is. Take your 11.25 and times it by .7
That gives you about 7.875 now that is just for one half of the side wall. So now you need to times the 7.875 x 2 that's 15.75 now add the rim size to that (17) and you have about 32.75.

So a 285/70/17 is about a 33x11.25x17. Hope that helps.:cheers:
 

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So as the title says "What does this even mean?"
I am looking at tire company websites and checking out the size tires they have available. and I keep seeing stuff like this 33X12.50R17LT. What the crap is this? Is this bigger or smaller than a 285/70/17? :mecry:
Pretty straight forward. 33 is the heigth, 12.50 is the width, R is radial, 17 is the rim size, LT is Light Truck. This is the old school way tires were descibed before metric tires became popular.

Just a bit smaller than the 285/70/17 which I assume will also be a radial.
 

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Discussion Starter #7
ahh ok. I knew it was a measurment in inches, but I didn't understand how he measured up to the normal measurments. So I relly couldn't tell if it was larger or smaller than the 285/70/17.

So the 33x12.50x17 is slightly smaller?
 

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As cnckart explained, the quick, easy way to convert a metric measured tire size (e.g., 285/70/17) into something equivalent to 33 x 12.5 (e.g., tire diameter and width in inches) is the following:

The first number on the metric sizing is the width of the tire in millimeters. Take it and divide by 25.4 to convert to inches. So 285/25.4 = 11.2 inches. That's the tire's width.

Multiplying the width by the second number in the metric sizing (which is the sidewall ratio and is expressed as a percentage) gives you the distance between the outer edge of the tire and the rim, or the measurement of the sidewall. So 285 x 70% = 199.5 millimeters. Again, to convert to inches divide by 25.4, so 199.5/25.4 = 7.85 inches. Now to determine the overall diameter of the tire, you must take the sidewall measurement, add in the rim size (which is the third number in the metric sizing and is actually measured in inches, so in this case it is 17 inches), and then add in a second sidewall as the rim has sidewall surrounding it (e.g., the diameter of the tire itself would consist of the measurement of two sidewalls and the diameter of the rim). So you have 7.85 inches (sidewall) + 17 inches (rim) + 7.85 inches (sidewall) = 32.7 inches.

So 285/70/17 = ~32.7 inches in diameter x 11.2 inches in width. The rim size is 17 inches.

Hope this helps.
 

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As I understand it a 285/70 is 285mm wide and 70% as tall
So 285 / 10 (convert to cm) = 28.5cm
28.5 / 2.54 (convert to inches) = 11.22"
11.22 * .7 (calculate sidewall height) = 7.85"

So a 285/70R17 would be 11.22/7.85R17

If my understanding or my math is wrong, please feel free to correct me :)

-cad
 

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Dammit. Beat to the punch. Stupid iPhone, took too long to type it out!

-cad
 

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ahh ok. I knew it was a measurment in inches, but I didn't understand how he measured up to the normal measurments. So I relly couldn't tell if it was larger or smaller than the 285/70/17.

So the 33x12.50x17 is slightly smaller?
No, i think someone misspoke right above you.


The 33x12.50 is slightly taller and an inch wider than a 285.
 

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ohh ok. Will a 3" and BC fit 33x12.50x17?


Thanks
On stock wheels definitely.

Aftermarket wheels depends on the backspacing.
 

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I have 285/70/17 on mine and they were real close to the stock UCA. That would be my only concern on that size. You could upgrade to aftermarket UCAs or run wheel spacers if it's a problem. I have upgraded my UCAs and have tons of room now.:cheers:
 

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Discussion Starter #19
I have 285/70/17 on mine and they were real close to the stock UCA. That would be my only concern on that size. You could upgrade to aftermarket UCAs or run wheel spacers if it's a problem. I have upgraded my UCAs and have tons of room now.:cheers:

I wish I was a fabricator. The gear for this rig is expensive. I would deff. like some UCA's and spacers, and lower rear top and bottom control arms as well. I may have to take a small loan for this stuff lOL :rofl:
 

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Metal Tech is having a group buy on OME suspension and LR UCA.

They are both at the cheapest i have ever seen them.
 
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