# OK a Tire Question about Sizes



## RedskinFan228 (Jun 28, 2004)

Alright guys in the know what do the numbers actually mea? I hought I knew but the more I read the more confused I get LOL which is really not that difficult for me 

OK here it is P265/75R/16 and P265/70R16 what is the difference. 

From what I was able to figure out the "260" is the width in MM and the 75 represents 75% of the width in sidewall hight from ground to rim. Is this correct? If so then basically these two tires would be the same width and the "75" slightly (almost unnoticable)taller????? 

Just asking because on some of the trucks I am looking at the ones with the optionable 4X4 packages (Xtera and Tacoma) come with the P265/75R/16 while the sport and SE, LE models come with the P265/70R16 I always thought the "70" ones were wider. 

Thanks

Ken


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## okimavich (Nov 13, 2006)

You are correct.

265 is the width of the tread in mm.

75 is the percentage of the side profile that is rubber.

R is "Radial" type 

16 is the side of the rims


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## narfpoit (Jun 16, 2004)

For the two sizes you are looking at the section width would be the same but the sidewall height would be about .52" taller on the 265/75/16 and the overall diameter would be 1.04" taller. So basically one is a 30 inch tire and one is 31 inch. Which really is only an extra half inch of clearance but it is nice to have in when you need it.


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## 1BadF350 (Jul 19, 2006)

okimavich is correct. I would add that the 75 is actually the height of the sidewall in expressed as a percentage of the width in mm. Therefore, given the tire size you provided, the height of the sidwall is 75% of 265mm or 198.75mm. 
Figure roughly 25mm/inch so your rim is 400mm in diameter. Multiply 198.75 by two (since you must account for both bottom and top sidewalls to find diameter). This equals 397.5mm + 400mm=797.5 mm/25=31.9" total diameter.


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## okimavich (Nov 13, 2006)

Here's a nice writeup on the tire codes


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## Woodchuck (Jan 5, 2005)

Here is a tire size comparison calculator.

http://www.miata.net/garage/tirecalc.html


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## RedskinFan228 (Jun 28, 2004)

Thanks guys so what I was reading was correct the 265/75 is actually a taller tire than the 265/70 both having the same width. Funny as I always thought that the lower second number was a wider tire LOL. I remember that from my days driving a hot rod. I had 70's on the front of my camaro and 60's on the back (60's were wider LOL). Same with my old 68 mustang. Guess things have changed in 25 years.

Ken


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## narfpoit (Jun 16, 2004)

RedskinFan228 said:


> Thanks guys so what I was reading was correct the 265/75 is actually a taller tire than the 265/70 both having the same width. Funny as I always thought that the lower second number was a wider tire LOL. I remember that from my days driving a hot rod. I had 70's on the front of my camaro and 60's on the back (60's were wider LOL). Same with my old 68 mustang. Guess things have changed in 25 years.
> 
> Ken


The 60's were wider and that is why the height was 60 percent of the width of the wider tire to match the height of the narrower tires in the front that had a 70 percent height to section width ratio.


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## chris storrs (Aug 25, 2005)

easier option..buy tires with the US measurements written on em

33x12.50s
31x10.50s(whats on our exterra)

i gave up tring to firgure out the other system

bimini twist..not a problem
265/70...no clue


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## jeep2obx (Jul 10, 2006)

reading tire size 265-75r-16.5 means that the tire is 265 tall 75r states how wide and that its a radial and 16.5 is rim size higher first number means taller tire,lower 2'nd number means wider tire and 3rd means rim size


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## 1BadF350 (Jul 19, 2006)

jeep2obx said:


> reading tire size 265-75r-16.5 means that the tire is 265 tall


No it doesn't. It means it's 265mm wide.


> 75r states how wide


No it doesn't. It's the aspect ratio. It means that the sidewall height is 75% of the width.


> and that its a radial and 16.5 is rim size


Thats the easy part.


> higher first number means taller tire,lower 2'nd number means wider tire


It's the opposite. A higher first number generally means wider, but will also mean taller, unless the aspect ratio is lower.


> and 3rd means rim size


You sure it doesn't mean the engine size?
 
Seriously, I know you were trying to help, but saying nothing is better than giving bad info.


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## bivalvebill (Feb 10, 2007)

31 x 10.50 on my frontier I know they will work on your's


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