33” tire rim width

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Shoote

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I have a 1987 4x4 short bed with the optional aluminum wheels. I believe they are 7” wide. Will 33 x12 tires be safe to install on these rims? I believe 32x11 will fit for sure but I would like to go bigger. Stock tire size for this truck is 31x10. Thanks in advance!
 

gmbellew

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I run BFG 33x10.5r15 on those rims. I believe the 12in wide tires are too wide for the 7in rim width.
 

dvdswan

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As a general rule, optimum width for tire/wheel combinations is 4". i.e. 8" rim with a 12" tire, 10" rim with a 14" tire. That being said. I've seen an 8" rim with a 14" wide tire. The tire looks squeezed and taller.
 

Grit dog

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As a general rule, optimum width for tire/wheel combinations is 4". i.e. 8" rim with a 12" tire, 10" rim with a 14" tire. That being said. I've seen an 8" rim with a 14" wide tire. The tire looks squeezed and taller.
You’re a little off there.
First using a hard dimension is not right.
Second in this case, 8” rim for a 12.50” tire would be about the absolute minimum without ballooning the tire.
.8-.9W is optimum. .7W is about the min acceptable.
 

Grit dog

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I have a 1987 4x4 short bed with the optional aluminum wheels. I believe they are 7” wide. Will 33 x12 tires be safe to install on these rims? I believe 32x11 will fit for sure but I would like to go bigger. Stock tire size for this truck is 31x10. Thanks in advance!
Need to be a little more sure about the rim width.
For wheeling I’d put a 12.50 on a 7” rim and run it. For street use, too narrow.
 

bucket

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Technically, the rim is too narrow. But, an incredible amount of people have run a 12.5 tire on a 7 inch rim and it has worked fine.
 

bucket

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Also, I've run a set of 15.5" width tires on an 8" wide rim before. I bought the tires used and they were on '94-ish F150 rims that were only 7" or 7.5" width.
 

75gmck25

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You might find a tire shop that can make a quick stock rim width measurement for you, just to verify what you have. They have a large set of calipers that just slips over the mounted tire and it gives them a measurement.

 

bucket

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If they are the factory aluminum wheels, they are 7" wide. The large calipers will read from the outside of the beads and show ~7.5" wide.
 

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I'm surprised no one has mentioned that tire manufacturers specify a range of rim widths for each tire. It'll be on their website. The 33x12.5's I've checked specify a minimum 8" rim. It seems like a bad idea to deviate from the manufacturer's specs on something on which safety depends so heavily, except maybe for low-speed off-road use.

I usually use the narrowest wheel a tire specifies, because it pulls the sidewalls in a bit, which provides some protection from curbs or rocks.
 

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