keep on ROLLIN'

[sreaminbronco]

for a 92' bronco will these tire specs. work? 31x10.50R15 T/A KO (Load Range=C O.D.=30.7) On stock 15x7.5 i think thats right. Right now I have 31x10.5x15.

 

[bluesman17]

whats the difference between what you have and want? im lost.

 

[texan79&96]

those are the same size...?

 

[Seabronc]

Yes, they will fit a stock 15 x 7.5 wheel. The two tires you listed are the same size.

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[sreaminbronco]

no im not asking about the size but people tell me i need load range D is this true?

 

[Bronco89XLT]

I had the same tire on my 97 F250LD without any problems!! As for the Bronco, right now I have 32x11.50x15 BFG Mud Terrains on 15x8 with very little rubbing at full left lock, none at right lock.

 

[Seabronc]

no im not asking about the size but people tell me i need load range D is this true?

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OK now that we understand the question, No manufacturer that I can find makes a 31x 10.5 with a load range other than C. A "C" load range means the max inflation pressure that the tire can handle is 50 psi. However, for a light truck this is reduced by 8% which makes the max pressure 45.5 lb.

Looking at the BFG spec. the max weight per tire is 2270 at 50 psi, so reducing that by 8% makes it 2088 at 45.5 psi. The Bronco weighs approximately 5000 lb divided by 4 comes out to approximately 1750 lb per tire, which means I only need 76% of the maximum designed 50 psi or 38 psi to have properly inflated tires to hold the Bronco weight.

My conclusion is that the 31 x 10.5 tire has plenty of safety margin to hold the weight of a Bronco. I run mine at 39 psi by the way.

The answer to your question, in my openion is NO you do not need load range "D" nor can you find such an animal. Load range "D" would apply to a much heavier vehicle, say in the 8500+ lb range.

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[sreaminbronco]

hey seabronc thanks for the help but your wrong on the weighs because the sticker on the inside of my bronco says 6500. lol

 

[Justshootme84]

6500 lbs. is the GVWR, or the max amount of vehicle plus cargo the Bronco is rated to carry. An empty Bronco does weigh in about 5500#. aND THE 31" tire is only offerd in a load range "C" for most brands. I run "D"=rated tires on another truck used for heavy towing and to reduce the number of flats. P285R75R16 size.

 

[rubberdust]

The 1992 Bronco came with a P235/75R15 XL tire in most instances but did offer a 31X10.50R15 as an option. The recommended inflation presure for the 235/75R15 is 35psi front & 41 psi rear. This was done as much for stability of the vehicle as it was for load. Ford want to keep us right side up so making it understeer even more was the goal.

With the tires your looking at with a 31X10.50R15/C, they have a maximum inflation of 50psi & will carry 2250lbs. You don't need to reduce the load carrying capacity of a light truck tire on a light truck.

When installing passenger tires on a light truck you then need to reduce the load carrying capacity by dividing the passenger tire load by 1.1 or approx. 9%

If you look in the books it will tell you 40psi both front & rear with the 31X10.50R15/C, the RMA & TRA don't break the charts down into single digits like they do for passenger tires.

For running down the hiway a little more in the rear will make it less twitchy.

A 7 inch wide wheel is just fine.

If you need the extra load of a load range D you will end up getting 16 inch wheels & going with a LT165/70R16/D it will carry 2835lbs @ 65psi but from a durability stand point both the 31X10.50R15/C & the 265/70R16/D use the same 3 ply sidewall. The 16/D will use a slightly heavier belt package.