Actual tire sizes

What would the actual height of a 285/75/16 BFG AT be? Also, a 275/70. We should work on a list of the actual height of a tire, not just what it is sold as. I understand the BFG's are a tad under-sized...?

Thinking about going to a 275 from my current 285's, I would lose about 1 1/4", by the calculator, but I am curious how the tire actually measures up.

 

He wants the actual size measured with a tape on your truck.
My BFG AT 285/75/17 sold as 33s
Calculator says they are 33.8
Measure 32.4 on my truck

The general rule of thumb is you lose about a 1/2 inch once the tires are mounted and truck weight is upon them. I didn't measure them without being on the truck so I can't give you that number.

 

For future referance, I'm not talking about the conversion or sizes as said by manufacturer. I am talking about ACTUAL size, the size of the tire measured by someone in the real-user world, not a company engineer. I've been all over this site, so I am fully aware of the "mods and tutorials" and the tires conversion. Thanks ...

 

Thank you. I know a 33" or 285 is not a full 33". Some brands run bigger than others ie: swampers seem to be on the bigger end, BFG and others seem to be under the stated sizes.

 

I'm chill. In my first post, I said "by the calculator". But whatever. It's all good.

 

differs from tire to tire

ive seen the same listed size vary close to an inch from different manufactures

 

I always wonder.. why do people refer to sizes shortened to just the width? a 285 could be a 24 inch tire depending on the aspect ratio and rim size.

 

You make a good point. Got another sammich?

 

I believe its because they don't fully understand how it is figured out.

 

Quite possibly. I never really cared to get all up in that number junk. I like the simple 33x12.5x16 numbers
Think you can explain it to us simpletons?

 

Play that violin boy!

 

$326+ BFGoodrich All-Terrain T/A KO2 Tires

http://www.tirerack.com/tires/tires...pecs&PID=1921853&SID=two1169718&AID=10398365&

285/75-R16 is listed as having 634 revs/mile
1 mile = 63,360 inches

So 63,360 / 634 / 2 / pi = 15.9" rolling radius

The tire is listed as having a free diameter of 32.8", so 32.8/2 + 15.9 = 32.3".

The tire would be 32.3" tall on the ground, presumably at the max load rating of 3305 lb at 65 psi max inflation pressure.

The rule of thumb of manufacturer's advertised dia. minus half inch is close enough.

 

Oh geeze you had to go ahead and post something that's going to make me think. Good GAWD.

 

No no! let the OP use a measurement taken by one guy on the ground running 30psi, and compare to another measurement by another member who runs 42psi and measures with the truck jacked up!

Dude, really, the manufacturers specs are as likely a basis for comparison as you're going to find. While the numbers may not be completely "real world" they're going to be pretty darn good for comparison from one tire to another from the same manufacturer.

 

Just look up the tire's free diameter on Tire Rack and subtract half an inch. Close enough for all intents and purposes.

Keep in mind the tire diameter will decrease slightly with tread wear.

 

285/70/R17

285- The tires width in Millimeters
70- Aspect Ratio 70% of the tires width in this case
R- For Radial Construction (I always thought it meant Rim)
17- Code for rim the tire fits on

You will usually have an additional 2 numbers and a letter.
The 2 numbers stand for what load the wheels can handle
The letter is the speed rating for this tire

Here are the 2 numbers and what they stand for


The letters
Q — Up to 100mph
S— Up to 112mph
T— Up to 118mph
H— Up to 130mph
V— Up to 149mph
Z — 149mph and over
W — Up to 168mph


The fact that the middle number is a percentage is what causes the confusion.

 

Read on page 1 he asked for me to explain how to read the numbers. Thanks for playing
I got it for you.

 

a

 

Another sammich! where is mine dammit! As for the mumbo-jumbo about a 285 and rotations per mile and inches in a mile and 32.8 divided by the distance from my coffee table to the bathroom sink plus the square root of the speed of light minus the distortion caused by Earth's rotation and gravity plus the weight of a sweated prostitute....... thanks for the break down.