37" - 12.50 vs. 13.50 widths

chiggerdude

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I'm installing the (just released) 2.5" Teraflex lift w/ springs on Monday.
I'm running Machete wheels with an aggressive 3.5" back spacing.
My question is; Has anyone found any pros or cons besides the weight of the 13.50 width vs 12.50 tire? I'm leaning more towards the 12.50 width. Some 13.50's just seem like too much tire, if there is such a thing.

 

NFRs2000NYC

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Well, there are pros and cons. A wider tire has less pressure of contact on the road, so in slippery conditions, it will slip easier than a thinner tire which exerts more pressure per inch on a surface. The plus size is it can offer more grip in dry conditions as well as certain situations offroad. For standing water, a thinner tire is better. For sand and powder snow, a wider tire will "float" better over the surface. Wider tire looks better. Wider tire will most certainly be heavier, in the case of cooper stt pros, it's 9lbs heavier, which is not insignificant. Some car washes can't take anything more than a 12.50. A wider tire will also have slightly more rolling resistance, which will impact MPG a little more, and cause more drag.
 
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chiggerdude

chiggerdude

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Well, there are pros and cons. A wider tire has less pressure of contact on the road, so in slippery conditions, it will slip easier than a thinner tire which exerts more pressure per inch on a surface. The plus size is it can offer more grip in dry conditions as well as certain situations offroad. For standing water, a thinner tire is better. For sand and powder snow, a wider tire will "float" better over the surface. Wider tire looks better. Wider tire will most certainly be heavier, in the case of cooper stt pros, it's 9lbs heavier, which is not insignificant. Some car washes can't take anything more than a 12.50. A wider tire will also have slightly more rolling resistance, which will impact MPG a little more, and cause more drag.
Very good answers. I had the bfg 37x12.50 on my 17 JKU... except for never getting them close to being balanced, they were awesome in all conditions.
I’m leaning towards the ridge graps or coop STTs this next go around.
My gut tells me to stick with 12.50. Thank you for the detailed reply.
 

NFRs2000NYC

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For the record, both a 12.50 and a 13.50 are considered fat tires. Pizza cutters (sub 10") do have their own advantages, like better grip on road in bad conditions, less tramlining, and in mud situations a thinner tire will sink to find the bottom and give you better traction than a "fat floater" but skinny tires aren't really a "jeep thing"....we like big meaty tires.
 

caged

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and 12.5 tires will fit on an 8-9 inch rim. 13.5 should go on 10 inch rim.
wider tires can air down a little more than narrow ones. (i like 5psi on beadlocks)
 


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and 12.5 tires will fit on an 8-9 inch rim. 13.5 should go on 10 inch rim.
wider tires can air down a little more than narrow ones. (i like 5psi on beadlocks)
13.5 inch wide tires can go on rims 8.5 inches and wider per most brand specs.
 

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sure they can. but it's easier to lose a bead when you air down. so i wouldn't recommend it.
 

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12.5/13.5 also often makes a diff in D vs E load rating
 

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Very good answers. I had the bfg 37x12.50 on my 17 JKU... except for never getting them close to being balanced, they were awesome in all conditions.
I’m leaning towards the ridge graps or coop STTs this next go around.
My gut tells me to stick with 12.50. Thank you for the detailed reply.
I have the 37 12.50 17 in the nitto ridge grappler and they are so quiet but after 43 yrs of driving with the mud tire it is nice to hear no noise but i miss that aggressive look of the mud tire so after 5000 miles on my ridge grapplers I am switching to the sst pros. will 37 13.50 really not be as good in wet conditions i read that the wider tire is not as good in rain ? any real truth to that ? and will the car wash let me go through with the 37 13.50 or 12.50 the widest it takes in that rack your tire goes in ? i have a great deal $14 a month unlimited at the car wash i dont want to go back to hand washes like i did on my dooleys and 40s 15.50. hand washes are $40 and i dont have time to wash it my self lol are the sst coopers that loud ? how to they compare to the toyo mt open country ? i gad those before and the toyos are not loud at all but a lot more money. i saw like about 80 more tie i the 37 12.50 17 thats a lot but i am sure its a lot better made.I like the look of the stt pros but i know a lot of people do get them because they are not very expensive of a tire over the nittos and toyos
 

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Well, there are pros and cons. A wider tire has less pressure of contact on the road, so in slippery conditions, it will slip easier than a thinner tire which exerts more pressure per inch on a surface. The plus size is it can offer more grip in dry conditions as well as certain situations offroad. For standing water, a thinner tire is better. For sand and powder snow, a wider tire will "float" better over the surface. Wider tire looks better. Wider tire will most certainly be heavier, in the case of cooper stt pros, it's 9lbs heavier, which is not insignificant. Some car washes can't take anything more than a 12.50. A wider tire will also have slightly more rolling resistance, which will impact MPG a little more, and cause more drag.
Its only 7 lbs more on the 13.50 vs the 12/50 on the copper sst pro.I have the 37 12.50 Nitto ridge grappler now for almost 6 000 miles and its so quit but i miss the aggressive look of the mt so i am either going with the 37 12.50 or 37 13.50 just dont know about the E rated tire but wondering if a 13.50 will walk going down the road side ways. but you would think the tire would be a 1 inch wider but go to coppers website and its says only .3 wider. that is not even half a inch wide. how can that be right ? it looks 1 inch wider but not on their chart
 


me109stock

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Its only 7 lbs more on the 13.50 vs the 12/50 on the copper sst pro.I have the 37 12.50 Nitto ridge grappler now for almost 6 000 miles and its so quit but i miss the aggressive look of the mt so i am either going with the 37 12.50 or 37 13.50 just dont know about the E rated tire but wondering if a 13.50 will walk going down the road side ways. but you would think the tire would be a 1 inch wider but go to coppers website and its says only .3 wider. that is not even half a inch wide. how can that be right ? it looks 1 inch wider but not on their chart
The width is somewhat influenced by the width of the rim the tire is mounted to when measured. That could account for the only 0.3" measured difference between the 1" different nominal measured width. Just speculating here though.
I'm looking at a great deal on some used 37/13.5R17 Toyo MTs but like others on this thread am not sure about that extra inch. With only 1400 miles on them though and half price I'm leaning toward pulling the trigger. I have BAD Eklipse wheels that are 17x10 so they should square up on them nicely and I think the 3.5" backspacing will prevent any issues with the 1" wider tire (though it might stick even further out from the fender.
 

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sure they can. but it's easier to lose a bead when you air down. so i wouldn't recommend it.
Wider tire and smaller rim actual acts as a poor man's beadlock, you will not throw a bead easier.

 

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