True Tire Size Database

[Carlton]

If you have been dealing with Jeeps or Trucks for awhile you are aware that tires do not measure up to what is stated on the sidewall or manufactures specs. We have all seen newbies complain that their 35 measures 33. Sorry, but it is normal for a tire to compress with a few thousand pounds sitting on it. The only brand I have seen measure taller is Interco.

One of the most common questions we see related to tires is: What do they measure? So I thought it would be great to make a database thread. There is a similar thread on [Banned Site] but I do not agree with their measurement process.

For your post please do the following:

1. State the brand & model of tire.
2. State the size listed on your tire
3. State your PSI
4. With a level across the top of your front passenger tire measure with a measuring tape. If you do not have a level, use a flat object. (A level is strongly preferred)
5. Post a picture and all above information.

View following post for example.

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[Carlton]

1. Milestar Patagonia MT
2. 40x13.50r17
3. 28 PSI
4. 39" tall

 

[blnewt]

Milestar Patagonia M/T E Load rating 295/70/17 (33.25" based on https://www.wheel-size.com/calc/ )
With OPs method (and yes, that is a level) and under load @ 30psi and being a front tire (which might be a bit shorter due to the heavier front weight).
32.75" so probably spot-on from what they should be
EDIT, measured rear tire and it's within 1/16" of the front so nothing significant.

 

[aai]

1. BFG KM3
2. 37 x 12.50 x 17
3. 31 psi
4. 35 3/4" tall

 

[American Adventurist]

1. BFG KO2
2. 37 x 12.50 x 17
3. 34 psi
4. 35.5 tall

I don’t feel like taking pics

 

[MyJlU]

I don’t feel like taking pics

Love the Enthusiasm

 

[four low]

The PSI is going to cause discrepancies, ie,the tire will deform according to the tire pressure.
If you used the diameter of the tire off the vehicle, or the spare if it matches, you will get a more accurate figure

 

[DURSO]

1. BFG KM3
2. 37 x 12.50 x 17
3. 31 psi
4. 35 3/4" tall

Same tires and measurments for me too

 

[D60]

The PSI is going to cause discrepancies, ie,the tire will deform according to the tire pressure.
If you used the diameter of the tire off the vehicle, or the spare if it matches, you will get a more accurate figure

This.

Measurements should be tire inflated and PSI stated (as well as wheel width) but should NOT be static loaded but rather unloaded.

THE BEST way to do this is a Pi tape. Failing that a cloth/fabric/nylon flexible tape and /3.1416.

Lufkin makes a nice Pi tape and easy to obtain via the interweb. Used the hell outta them when machining HDPE pipe liners 'cause nothing about plastics stays round. The cool thing with the Pi tape is you can pretty easily measure within 10 thou (and better) using just a tape

 

[four low]

This.

Measurements should be tire inflated and PSI stated (as well as wheel width) but should NOT be static loaded but rather unloaded.

THE BEST way to do this is a Pi tape. Failing that a cloth/fabric/nylon flexible tape and /3.1416.

Lufkin makes a nice Pi tape and easy to obtain via the interweb. Used the hell outta them when machining HDPE pipe liners 'cause nothing about plastics stays round. The cool thing with the Pi tape is you can pretty easily measure within 10 thou (and better) using just a tape

Yes, agree. Tire inflated, but not loaded, ie, off vehicle, or vehicle raised , say on a lift.

 

[Carlton]

This.

Measurements should be tire inflated and PSI stated (as well as wheel width) but should NOT be static loaded but rather unloaded.

THE BEST way to do this is a Pi tape. Failing that a cloth/fabric/nylon flexible tape and /3.1416.

Lufkin makes a nice Pi tape and easy to obtain via the interweb. Used the hell outta them when machining HDPE pipe liners 'cause nothing about plastics stays round. The cool thing with the Pi tape is you can pretty easily measure within 10 thou (and better) using just a tape

Yes, agree. Tire inflated, but not loaded, ie, off vehicle, or vehicle raised , say on a lift.

Nobody cares what a tire measures off the jeep. They want to know what it measures under the jeep. There may be a slight variance due to PSI that is why it is included.

 

[SilverRubi]

I'm going to give this a bump. Interested to see what others are measuring their tires at on the Jeep. I just ordered a 3.5 Gamechanger and still debating tires. Would like to see how the KM3s, Toyo MTs, Patagonias, and Trail Grapplers compare to each other.

 

[Martial Fartist]

Been too long since the last post. It needs a bump.
Love reading these threads.

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