Copperhead7310
Senior Member
- Joined
- Jul 21, 2014
- Posts
- 161
- Reaction score
- 33
- Location
- Chattanooga TN
- Ram Year
- 2014 Big Horn CCSB
- Engine
- Hemi 5.7
Man this is a great thread.
I read a couple tire size questions earlier and thought I could help.
Ex 275/55/20
275 / 25.4 will give you the width of the tire tread (different than section width) in inches. = 10.82" wide
The next number is the aspect ratio. 55
This is 55% of the width, to determine the height of the sidewall. In other words the height from the ground to the bottom edge of the wheel lip, .. likewise from the top edge of the wheel lip to the top of the tire tread. 10.82 * .55 = 5.95 The tire sidewall will be 5.95" tall.
We have two of those. Top, and Bottom.
Now add your wheel diameter.
So, 5.95 * 2 + 20 = 31.9" The tire overall height / diameter.
275/25.4*.55*2+20 vs. stock 275/25.4*.60*2+20 = 32.99"
The tires are about an inch shorter but remember it's only half that. the other 1/2 will be seen as 'drop' You'd only see 1/2" difference at the wheel lip. Not the full 1" difference thinking wheel hub center.
I read a couple tire size questions earlier and thought I could help.
Ex 275/55/20
275 / 25.4 will give you the width of the tire tread (different than section width) in inches. = 10.82" wide
The next number is the aspect ratio. 55
This is 55% of the width, to determine the height of the sidewall. In other words the height from the ground to the bottom edge of the wheel lip, .. likewise from the top edge of the wheel lip to the top of the tire tread. 10.82 * .55 = 5.95 The tire sidewall will be 5.95" tall.
We have two of those. Top, and Bottom.
Now add your wheel diameter.
So, 5.95 * 2 + 20 = 31.9" The tire overall height / diameter.
275/25.4*.55*2+20 vs. stock 275/25.4*.60*2+20 = 32.99"
The tires are about an inch shorter but remember it's only half that. the other 1/2 will be seen as 'drop' You'd only see 1/2" difference at the wheel lip. Not the full 1" difference thinking wheel hub center.
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