Best 315/75R16 All-Terrain tire?

[JeepZilla380]

I was on D rated Maxxis Mudders 285/75r16 on my stock Moabs and they were horrible. Switched to the sam size Duratrac and its a night and day difference. My Duras are E Rated, but ride nice and have done well offload. That being said, if I ever need another set of tires, or went to 35s I would get 15 in wheels.

 

[Mr. Bills]

Still happy with those tires? I’m considering those against E rated Duratracs and D rated Nittos and even the D rated MT/Rs. Gotta decide soon

Yes, I am. I just returned from a 5-day offroading trip with 500 miles of highway driving to and from, most of it 75 mph Interstate. The MT Baja ATZ P3 tires worked well for the varied conditions.

 

[Mr. Bills]

. . . KO2s are great in the 315 in C rating, but your basically buying a 33 and not a 35. BFG needs to get their shit together with the sizing.

BFG never claims that its 315/70R17 A/T KO2 is a 35" tire. That size may be popularly known as a "metric 35", as is a 315/75R16, but no manufacturer uses that term and every manufacturer publishes the measured diameters of each size when mounted and inflated, which in this case is 34.4" - more than 33".

. . . Any brands that are notoriously undersized I should ignore?

Its not a question of a particular brand being undersized as much as whether the tire with the features and qualities you value most comes in a diameter that works for you.

Using the example of the three LT315/75R16 tires mentioned and the LT315/R17 BFG KO2, the BFG has a published published diameter of 34.4" mounted on a 9.5" rim inflated to the rated pressure of 45 psi for the C load rated version and 65 psi for the E load rated version. The Goodyear Duratrac and MTR "metric 35's" are both listed at 34.8" in diameter on 8.5" rims, the E load rated Duratrac at 65 psi and the D load rated MTR at 50 psi. The Mickey Thompson 315/75R16 "metric 35" has a listed diameter of 34.5" on an 8.5" rim inflated to 65 psi.

So the question is, does the 0.4" difference in listed diameter between the Goodyears and the BFG's or the 0.3" difference in listed diameter between Goodyears and the Mickey Thompson's really matter for how you wheel and where you wheel.

Much ado about nothing if you ask me, especially since the measurement that matters is not the diameter but the rolling radius.

 

[Starrs]

BFG never claims that its 315/70R17 A/T KO2 is a 35" tire. That size may be popularly known as a "metric 35", as is a 315/75R16, but no manufacturer uses that term and every manufacturer publishes the measured diameters of each size when mounted and inflated, which in this case is 34.4" - more than 33".




Its not a question of a particular brand being undersized as much as whether the tire with the features and qualities you value most comes in a diameter that works for you.

Using the example of the three LT315/75R16 tires mentioned and the LT315/R17 BFG KO2, the BFG has a published published diameter of 34.4" mounted on a 9.5" rim inflated to the rated pressure of 45 psi for the C load rated version and 65 psi for the E load rated version. The Goodyear Duratrac and MTR "metric 35's" are both listed at 34.8" in diameter on 8.5" rims, the E load rated Duratrac at 65 psi and the D load rated MTR at 50 psi. The Mickey Thompson 315/75R16 "metric 35" has a listed diameter of 34.5" on an 8.5" rim inflated to 65 psi.

So the question is, does the 0.4" difference in listed diameter between the Goodyears and the BFG's or the 0.3" difference in listed diameter between Goodyears and the Mickey Thompson's really matter for how you wheel and where you wheel.

Much ado about nothing if you ask me, especially since the measurement that matters is not the diameter but the rolling radius.

Yep just what I said the 315 or more commonly called “35” is not even close to a 35” tire. Not even close to the 34.4” they claim. It’s on my jeep currently and measures 33”. Thanks for repeating everything I said haha. Damn and I just retyped everything I previously said in my post that you commented on. Anyway I think my point is made that BFG gives grossly inaccurate tire sizes to the public.

 

[Mr. Bills]

. . . the 315 or more commonly called “35” is not even close to a 35” tire. Not even close to the 34.4” they claim. It’s on my jeep currently and measures 33”. . . .

Comparing a measurement of tire diameter with your jeep is on the ground to the off-the-ground diameters published by the tire manufacturers is patently ridiculous. Of course the diameter measured from the ground to the top of the tire is going to be less than the diameter measured with the same tire off the ground. Your measuring method is further flawed because the results will vary from vehicle to vehicle depending on vehicle weight even if the rim width and inflation pressures are the same.

The dimension that matters is rolling radius. Look it up. Hint: @mrblaine has explained it more than once.

 

[mrblaine]

Anyway I think my point is made that BFG gives grossly inaccurate tire sizes to the public.

Only to that portion of the public that is measurement challenged. Polite way of saying goober, but goober with a tape measure nonetheless.

 

[Starrs]

Comparing a measurement of tire diameter with your jeep is on the ground to the off-the-ground diameters published by the tire manufacturers is patently ridiculous. Of course the diameter measured from the ground to the top of the tire is going to be less than the diameter measured with the same tire off the ground. Your measuring method is further flawed because the results will vary from vehicle to vehicle depending on vehicle weight even if the rim width and inflation pressures are the same.

The dimension that matters is rolling radius. Look it up. Hint: @mrblaine has explained it more than once.

No need. I have a 33” tire on my jeep. Good enough for me. I could inflate this all the way up and I wouldn’t get 34.4” out of it. BFGs are widely known for being grossly inaccurate with their tire sizes. Look it up.

 

[Starrs]

Only to that portion of the public that is measurement challenged. Polite way of saying goober, but goober with a tape measure nonetheless.

You lost me goober

 

[mrblaine]

You lost me goober

Tire size according to their dimensions is measured horizontally on the rim size they recommend. Tire size on the rig is measured from the center of the hub to the ground to determine rolling radius or that dimension doubled so you can figure out gear selection, speedometer correction etc.. They are not now nor will they ever be the same unless you make them out of iron or some other incompressible substance that will not allow the height from the hub down to change when the tire is loaded with the vehicle's weight. Did you ever happen to notice that tires on vehicles are a bit flatter where they contact the ground than they are around the whole rest of the tire?

 

[Starrs]

Tire size according to their dimensions is measured horizontally on the rim size they recommend. Tire size on the rig is measured from the center of the hub to the ground to determine rolling radius or that dimension doubled so you can figure out gear selection, speedometer correction etc.. They are not now nor will they ever be the same unless you make them out of iron or some other incompressible substance that will not allow the height from the hub down to change when the tire is loaded with the vehicle's weight. Did you ever happen to notice that tires on vehicles are a bit flatter where they contact the ground than they are around the whole rest of the tire?

Lol I’m not gonna get into one of these Blaine offs with you...I know that what I have on my jeep is a tire that is supposed to be 34.4”. I am not even close to that. That’s all. That’s all I’m saying. Please don’t tell me to go F myself

 

[Steel City 06]

So I would assume that the revolutions per mile is based on a target weight to inflation pressure, or target contact patch size.

For the Goodyear MT/R 315/75R16 or 35x12.5R15 the stated (unloaded) diameter is 34.8 and there are 598 revs per mile. 598 revs per mile yields an effective rolling radius of 33.7 inches.

Or the deflection of the tire is 0.54 inches from rest at the center of the contact patch. Thus the contact patch is 8.5 inches long, per the chord length equations. Assuming the tread width (not a provided specification) is 11 inches, then the contact area is approximately 88 square inches. At 3,195 lbs this comes out to be about 36.3 psi, which is a bit low for that weight given that the maximum pressure is 50 psi. But still reasonable.

The contact patch math is an approximation, as it ignores sidewall and other forces in the tire.

The manufacturer likely leans on the side of lower stated revs per mile for liability reasons. So I could easily believe that the MT/Rs are actually 34.8 or close to it

 

[Mr. Bills]

So I would assume that the revolutions per mile is based on a target weight to inflation pressure, or target contact patch size. . . .

Assumptions are dangerous.

Revolutions per mile is based upon circumference, which is constant whether or not the tire is weighted.

 

[Starrs]

@Chris what do your 315/17 KO2s measure at?

 

[Chris]

@Chris what do your 315/17 KO2s measure at?

33.25"

 

[Starrs]

33.25"

So my math may be off a bit but would you consider that to be grossly inaccurate from the figure BFG claims of 34.4” lol

 

[Chris]

So my math may be off a bit but would you consider that to be grossly inaccurate from the figure BFG claims of 34.4” lol

I would consider it to be extremely inaccurate. Keep in mind I took that measurement at 32 psi as well, so it's not like they were super low.

That's also on a brand new tire, as I measured them right after driving home from having them installed.

A 37" BFG is actually 35.2" I believe it is.

BFG is full of shit when it comes to the sizes of their tires.

 

[Starrs]

I would consider it to be extremely inaccurate. Keep in mind I took that measurement at 32 psi as well, so it's not like they were super low.

That's also on a brand new tire, as I measured them right after driving home from having them installed.

A 37" BFG is actually 35.2" I believe it is.

BFG is full of shit when it comes to the sizes of their tires.

I feel your pain

 

[Starrs]

I would consider it to be extremely inaccurate. Keep in mind I took that measurement at 32 psi as well, so it's not like they were super low.

That's also on a brand new tire, as I measured them right after driving home from having them installed.

A 37" BFG is actually 35.2" I believe it is.

BFG is full of shit when it comes to the sizes of their tires.

The 37” km3 or km2 will give you a true 35” tire...mounted on your jeep. Measured from the ground to the top of the tire lol

 

[Chris]

The 37” km3 or km2 will give you a true 35” tire...mounted on your jeep. Measured from the ground to the top of the tire lol

Haha! And then it all goes back to the dilemma of not wanting a damn E rated tire. Though I would settle for D.

 

[Starrs]

Haha! And then it all goes back to the dilemma of not wanting a damn E rated tire. Though I would settle for D.

D would be doable, but an E rating I don’t think I could do again. It’s rough lol