12.50" Wide Tires on 15"x 8" Stock Wheels?

TJOregon

TJOregon

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Hello all!

Current stock wheels are 15" x 8" Ravine Aluminum. Upgrading to 33" tires. Called TireRack.com and they said you need a minimum of 8.5" wheels and that my wheels are 1/2" too narrow for 12.50" wide tires. Can I push it and be ok? What's your experience? What's the downside?

Thanks!
 
It's fine... when I first upgraded to 33s I bought a used set of the original MT/R that were already mounted on 15x7 rims and ran them until bald. Just ensure you maintain proper pressure and rotate.

The challenge may be finding a shop that will mount them for you.
 
The internet says you cannot do it, and I have the same question. But I see so many folks that run the ravines and 33’s so I’m looking forward to hearing what folks experiences are. I’m running 32’s 11.5” on ravines and plan on going to 33’s when I wear these out. Seems like you just adjust the tire pressure to get an even wear across the tread.
 
That's what most people here with 12.5 tires are using and recommend (not necessarily stock, but 8" wide).

You'll need spacers to do that with ravines though. They have too much backspacing and you'll rub your control arms. 1.5" ought to be enough, you might be able to get by with 1.25".

I have 35x12.5 on 15x8 with 5.25" backspacing and 1.25" spacers for an effective backspacing of 4".
 
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freedom_in_4low said:
That's what most people here with 12.5 tires are using and recommend (not necessarily stock, but 8" wide).

You'll need spacers to do that with ravines though. They have too much backspacing and you'll rub your control arms. 1.5" ought to be enough, you might be able to get by with 1.25".

I have 35x12.5 on 15x8 with 5.25" backspacing and 1.25" spacers for an effective backspacing of 4".
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What psi do you run your 35’s at?
 
I've got 35x13.5x15 mounted on 8in rims. Most everyone on 35x12.50x15 around here runs 8in wide rims. You'll be just fine.
 
So far as I know all OE 'factory' wheels have too much backspacing for 12.5" wide tires even when they are 16x8. Unless they changed the backspacing for 16" wheels I believe they have 5.25" to 5.5" of backspacing which is too much for a 12.5" wide tire. The amount of backspacing is what controls the tire's inside sidewall clearance away from the suspension and frame.

For me I'd want no more than 4" of backspacing, which is what I have now, and even that requires a washer each of the two steering bolt stops. 3.75" is a common amount of backspacing for 12.5" wide tires.
 
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I ran 35 X 12.5 tires on a 15 X 8" wheel for years and never lost a bead. It's a great wheel for a 33 X 12.5. Though better for wheeling than street driving.
 
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freedom_in_4low said:
That's what most people here with 12.5 tires are using and recommend (not necessarily stock, but 8" wide).

You'll need spacers to do that with ravines though. They have too much backspacing and you'll rub your control arms. 1.5" ought to be enough, you might be able to get by with 1.25".

I have 35x12.5 on 15x8 with 5.25" backspacing and 1.25" spacers for an effective backspacing of 4".
Click to expand...
Can you recommend quality backspacers? Brand? Thanks.
 
TJOregon said:
Can you recommend quality backspacers? Brand? Thanks.
Click to expand...
Wheel spacers? Spidertrax, Synergy are two that have good records. Though I don't really know of any that have had problems that weren't the result of poor installation.

But backspacing doesn't address the supposed problem of wheel width your tire shop is claiming there is.
 
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jjvw said:
Wheel spacers? Spidertrax, Synergy are two that have good records. Though I don't really know of any that have had problems that weren't the result of poor installation.

But backspacing doesn't address the supposed problem is wheel width your tire shop is claiming there is.
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Thanks. I hear ya. I called two tire chains and they said they would install them. No problem. TireRack is the outlier.
 
jjvw said:
Wheel spacers? Spidertrax, Synergy are two that have good records. Though I don't really know of any that have had problems that weren't the result of poor installation.

But backspacing doesn't address the supposed problem is wheel width your tire shop is claiming there is.
Click to expand...
Many tire shops won’t install if it’s outside the manufacturers specs.

Example, ordered from Summit a few years ago. Tires and wheels are supposed to ship mounted and balanced but since the tire manufacturer said I needed at minimum 8.5” wheels Summit wouldn’t mount the tires on my new 8” wheels. The guy at Summit even said he knew people mount them all the time but he couldn’t do it nor did they have a release waiver I could sign.

Discount tire mounted them for me without question.
 
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Apparition said:
Many tire shops won’t install if it’s outside the manufacturers specs.

Example, ordered from Summit a few years ago. Tires and wheels are supposed to ship mounted and balanced but since the tire manufacturer said I needed at minimum 8.5” wheels Summit wouldn’t mount the tires on my new 8” wheels. The guy at Summit even said he knew people mount them all the time but he couldn’t do it nor did they have a release waiver I could sign.

Discount tire mounted them for me without question.
Click to expand...

Discount also mounted my 35x12.5 on 15x8 no questions. I don't even remember them asking me for a wheel size when I bought the tires.
 
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Apparition said:
Discount tire mounted them for me without question.
Click to expand...

Discount did mine also.

@TJOregon I am using Spidertrax 1.5" spacers with 35/12.50R15 on Canyon rims.
tires005.jpg
 
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