Police wheel Question?

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sabre67

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What was the standard size of a oem police style rim? 15x? Thanks for your help
 
They made a few different sizes depending on the year and model, but I’m guessing you are wondering about the common 15” slotted hole type used during the late 70’s-80’s? Those were all 15x7 and used a snap on hub cap
 
Yep, 15 x 7 and yes they are Heavy, Heavy.

Lots of rotating mass to spin up there every time you take off and slow down.
 
15x7 with a 4.25" backspace. About 25 lbs each.

img_3620-jpg.jpg


Going to 18x9's and 275/35/18's and 18x10's with 295/35/18's shaved weight from the 15x7" cop wheels with 225/60/15's.
tireweights_zpsf3d39dce-jpg.jpg
 
15x7 with a 4.25" backspace. About 25 lbs each.

View attachment 1715991551

Going to 18x9's and 275/35/18's and 18x10's with 295/35/18's shaved weight from the 15x7" cop wheels with 225/60/15's.
View attachment 1715991552
What's the backspacing on the 18s? I want to swap my Duster from 14/15" Rallys to 17s, but am terrified of spending a pile of money and finding out that the wheels do not fit.
 
What's the backspacing on the 18s? I want to swap my Duster from 14/15" Rallys to 17s, but am terrified of spending a pile of money and finding out that the wheels do not fit.

My 18x9’s have a +35mm offset, so that’s a 6.38” backspace. The DoctorDiff 13” brake kit I run adds about 5mm, so effective backspace compared to a 73+ mopar disk is about 6.2”.

With 17’s though you can’t go that deep, the outer tie rod end will hit the lip of the rim on a lot of 17” wheels if you go past about 5.7”. It depends on the design of the wheel, there are some that can do more but with 17” I wouldn’t go past 5.7”, which also means a 255 is about the widest you can safely go without significant fender mods
 
255 is fine-I was honestly thinking 225 or 235. (I know that 235/55R17 is a common tire size.)

So...17x7 should work...probably 5" backspacing...right? (Which is...what offset? Crap, I'm confused.)
 
255 is fine-I was honestly thinking 225 or 235. (I know that 235/55R17 is a common tire size.)

So...17x7 should work...probably 5" backspacing...right? (Which is...what offset? Crap, I'm confused.)

So for a 235 in the front you’d have to run a 235/45/17, even a 235/50/17 is 26.3” tall which will be tough to clear in the front because of the height. For a 235/45/17 you’d need at least a 17x7.5, I’d just run a 17x8. You’d want 5.25” of backspace for that so you’d be looking at +18 for the offset, and anything up to 5.7” would be fine.

For a 225 you’d be looking at a 225/50/17, that would be 25.9” tall and would work on 17x7 and for a 5” backspace you’d be looking at a +25 offset.

For the rears I’d need to know what axle you’ve got
 
So for a 235 in the front you’d have to run a 235/45/17, even a 235/50/17 is 26.3” tall which will be tough to clear in the front because of the height. For a 235/45/17 you’d need at least a 17x7.5, I’d just run a 17x8. You’d want 5.25” of backspace for that so you’d be looking at +18 for the offset, and anything up to 5.7” would be fine.

For a 225 you’d be looking at a 225/50/17, that would be 25.9” tall and would work on 17x7 and for a 5” backspace you’d be looking at a +25 offset.

For the rears I’d need to know what axle you’ve got
Will have 2.71 next spring.

My brain hurts.
 
So for a 235 in the front you’d have to run a 235/45/17, even a 235/50/17 is 26.3” tall which will be tough to clear in the front because of the height. For a 235/45/17 you’d need at least a 17x7.5, I’d just run a 17x8. You’d want 5.25” of backspace for that so you’d be looking at +18 for the offset, and anything up to 5.7” would be fine.

For a 225 you’d be looking at a 225/50/17, that would be 25.9” tall and would work on 17x7 and for a 5” backspace you’d be looking at a +25 offset.

For the rears I’d need to know what axle you’ve got
Does this apply to Darts as well?
 
They were 7" wide and the Super Coupes and Aspen R/Ts used a special 8" version.
 
Thanks Blu! If the size were 17x7 instead of 17x8, does the backspacing change?

It doesn’t have to, with a 17” rim ~5.7” remains the maximum. With a 17x8” about 5.25” is a good amount, so with 17x7 keeping the wheel in the same spot would be more like 4.75”. I wouldn’t run less than 4.25”, but since you’re going to be limited to nothing wider than a 225 on that 17x7 even up to 4.25” of backspace would work.
 
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