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Widest tires

Big AL

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A quick question... What is the widest tire you can mount on 8 1/2 wide Rims on 15inch rear Wheels right now
I'm running P255X60X15

Thanks in Advance for any help.
 

Chryco Psycho

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I ran a 295 but it was very close to the body , I ended upchanging to a Nitto 275 50 , I don't like the 275 60 , it looks too tall .
 

moparleo

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Big AL

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8 1/2" tells me it is an alloy wheel. What car are you installing this on and what is the backspace ? The alloy wheels and steel wheels are often different.
This are for my 70 Challenger and the wheels are Magnum 500s as for the back space I don't know it's all Stock.... Hope that helps. Thanks.... P235X60X15 Front P255X60X15 rear.
 
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moparleo

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The wheels are not stock, that is the reason you need to know the backspace. It is easy to measure with the rims off. Use the calculators I have posted to answer your questions on fitting your car with that wheel.
 

Big AL

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The wheels are not stock, that is the reason you need to know the backspace. It is easy to measure with the rims off. Use the calculators I have posted to answer your questions on fitting your car with that wheel.
Moparleo.. Thanks.
 

moparleo

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Post #4 originally said Torque thrust that is why I said they were not stock. But then again 15" Magnums were not factory either.
The alloy wheels generally had a compromise backspace so they could be used for different brand and model cars. They only had to change the bolt pattern.
2 piece rims like the Magnums could have the center moved to change backspace and so are easier to get a good fit.
 

heminut

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Moparleo is right, the backspace info is needed. It's hard enough to diagnose stuff over the internet, the more info the easier it is to make an educated guess, and that's what you are getting, a guess. The info is worth what you pay for it.
 

Mopar Mitch

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With the proper offset (backspacing), a 275-60-15 (15" diameter, correct?)... is no problem at all.

A 295-50-15 (hard to find) can be a problem pending the rim, would be pinched at the sidewalls... but again the offset (backspacing) is critical.

ZERO offset should be the magical number (keeping the rim centered within the wheelwell).

Do you know how to measure the backspacing?... Measure the entire rim width outer-to-outer, then take a block of wood or straight-edge and lay it across the rear... then measure in towards the back of the wheel where it mates the brake face hub (drum face).

IF you truly have an 8.5" width rim (advertised), chances are the overall width will be about 9.5". Divide that by 2 and you'll get 4.75".. which would then center the rim (zero offset)... and keep the wheel centered within the wheelwell. A 275-60 should fit easily... probably NOT even needing the fenderwell lips to be flushed (but that's a good thing to do for peace-of-mind pending a soft suspension).

Realistically, you can draw this all out on paper and see the effects that happen with different setups. I believe there's some apps that can do it for you.

Note: I'm currently running 18x11 rims , 5.5" backspacing... and 295-30-18 tires front and rear... lips flushed... stiff autocross suspension.
 

Big AL

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With the proper offset (backspacing), a 275-60-15 (15" diameter, correct?)... is no problem at all.

A 295-50-15 (hard to find) can be a problem pending the rim, would be pinched at the sidewalls... but again the offset (backspacing) is critical.

ZERO offset should be the magical number (keeping the rim centered within the wheelwell).

Do you know how to measure the backspacing?... Measure the entire rim width outer-to-outer, then take a block of wood or straight-edge and lay it across the rear... then measure in towards the back of the wheel where it mates the brake face hub (drum face).

IF you truly have an 8.5" width rim (advertised), chances are the overall width will be about 9.5". Divide that by 2 and you'll get 4.75".. which would then center the rim (zero offset)... and keep the wheel centered within the wheelwell. A 275-60 should fit easily... probably NOT even needing the fenderwell lips to be flushed (but that's a good thing to do for peace-of-mind pending a soft suspension).

Realistically, you can draw this all out on paper and see the effects that happen with different setups. I believe there's some apps that can do it for you.

Note: I'm currently running 18x11 rims , 5.5" backspacing... and 295-30-18 tires front and rear... lips flushed... stiff autocross suspension.
Thanks for the information much Appreciated.
 

6PKRTSE

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I run 295's on several sets of 15x8 rear wheels.
 

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