Does rim width affect what tire size I can use

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Pa's Toy

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Hello all...might be a simple question but as I am looking into upsizing my 13 inch rims to 14 inch ones, I thought I'd ask the following:
I have a set of SBP x 4.5 steelies and a set of SBP 14 x 5.5 rally wheels. I am trying to decide whether to go with 185/75r/14 inch tires or 205/70r/14 tires. From some reading I've done I am wondering if both tire choices are too wide for the original 4.5 rims? I likely will go with the 5.5 rally wheels . I have the centers and beauty rings for them and I also have a nice full hub cap as well. That said I am wondering if others are using the 4.5 inch wide rims for these tire sizes. Thoughts? With thanks.
 
Google it, and you can find proper rim width for tire size
 
The answer is "yes". The tire manufacturer will have a recommended minimum rim width for each tire size. These are shown in the specs on the Tire Rack website, for example.

From experience, 185 is fine on the 4.5" rim... probably 205 as well. 215 is OK on the 5.5" rim — I have 215/70-14 on my rally wheels.
 
Did so but received conflicting advice.... for example one thread spoke about a general rule of thumb of a tire width being no more than 2 inches more than the width of the rim. Other sites disagree with this ratio. Others suggest that 185/75r/14 will fit on a 4.5 but anything wider should be on a 5.5...thought I'd ask people with more hands on experience with these sorts of things
 
Pa's Toy said:
Did so but received conflicting advice.... for example one thread spoke about a general rule of thumb of a tire width being no more than 2 inches more than the width of the rim. Other sites disagree with this ratio. Others suggest that 185/75r/14 will fit on a 4.5 but anything wider should be on a 5.5...thought I'd ask people with more hands on experience with these sorts of things
Click to expand...

You can't use a "rule of thumb" that only considers rim width and tire width. The sidewall height has A LOT to do with how much tire can overhang the rim.

For example, a 275/60/15 has an ~11" section width and can be mounted safely on a 15x7.5". A 275/35/18 on the other hand still has an ~11” section width, but requires at least an 18x9” rim.

That’s an extreme case because of the different rim diameters, but even with the same diameter rim the height of the tire has a significant effect on the width of tire that can be mounted on a particular rim.

All tire manufacturers post their minimum and maximum recommended rim widths for each tire.
 
The 185’s would be perfect for the 4.5” rims, the 205’s would be fine on the 5.5” rims, but you could go 215” if you so desired.
 
Thank you all for your input....it helps and looks like I'm set for both tire sizes...one last question....any fitment issues with running the 205's versus the 185's on a 64 Barraucda with stock steering and suspension ?
 
the general rule of thumb I've heard for 60/70/75 aspect ratio tires is max tire width is 1.4-1.5x the rim width. I did run 195/70's on the stock 4.5" rims, and 195/70 front and 215/70 rear on 5.5" rallyes.
 
Pa's Toy said:
Thank you all for your input....it helps and looks like I'm set for both tire sizes...one last question....any fitment issues with running the 205's versus the 185's on a 64 Barraucda with stock steering and suspension ?
Click to expand...

You should be fine with those front tires. I'm running 215/65-15's on the front of my 66 Valiant with no issues whatsoever.
 
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