Im curious as to what the height or size difference of 265/70-18 and 275/65-18. would be.
Also what changes would be needed to fit either size onto a stock Sahara?
Lift and spacers????
Thanks.

 

265/70-18 is 32.6" tall and has a section width of 10.4" and a section height of 7.3"

275/65-18 is 31.6" tall and has a section width of 10.4" and a section height of 6.8"

Of course this doesnt take into account sizing differences from manufacturers.

 

I think you mean 30.4" tall...

 

So that you can figure it out yourself...

Take the first number (the tire width in mm) times the second number (the tire heigh expressed as a percent of the width - remember it's a percent so x .70 or .65) and that is the distance from rim to tread in mm. Then multiply that by 2 (because the tire is on both sides of the rim so to speak). Then convert that number to inches or convert the 3rd number to mm (the rim size in inches). Add them both together and you have the overall tire height.

 

OK Thanks for the replies.
The tires Im looking at are Falken Rock Mountain ATS.
They are the only ones Iv found for 18" rim.

 

Or, for 265/70-18:

18 + {[(265/25.4) * 0.7] * 2} = 32.6

 

I just went through this battle about 2 weeks ago and found that although these formulas will give you the reasoning behind the measurements, it really varies greatly between manufacturers. See if you can get exact dimensions from their websites.

 

There is quite an assortment of tires available for 18" rims" Take a look at Discount Tires Direct in the sponsor portion of this forum.

 

I have 315/70/R17

(315) x .03937 = 12.40155 = conversion

12.40155 x 2 = 24.8031

(24.8031) x (70/100) = 17.36217 = sum of sidewall minus wheel height

17.36217 + (17" wheel) = 34.36" in diameter not installed

Now, installed is a different story and can vary by wheel width, psi you're running, weight of Jeep and/or bumpers, etc.

my tires, at 34.36" in dia, once installed under the weight of my JK at 35 psi on a 9" wide rim and the weight of mods, I'm around 33.5" tall.

I think my math is correct

 

According to the tire chart in JP march 11 edition, 265/70R17 is 31.6 and the 285/70R17 is 32.7 both with a 10.4 width. I have to believe it would not be much diff going to an 18 inch rim. I was told by my JK dealer that anything over a 275 will rub without a lift, but the magazine states u can run a 32 inch tire without fender trim. So, that would mean a 255/R70 in 17. I know your asking about 18 but they only have 15-17 inch on chart