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Discussion Starter #1
Ok so I narrowed down my choice of wheel... i was thinking of 20x9.5 all the way around,,, with 18 offset,, will this work up front on a lowered car? I have coilovers but od rather keep it as low as I can. Will they stick out too far in the front? Ive heard ppl with vipers have the same offset? but is this for the front aswell? What size tries are you running also. I wanna use a 255/45/20 up front with that offset.
 

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I'm running a 20x9.5 with a +20 offset on a '12 SRT8 lowered on Hotchkis springs. I'm also running a 275/40/20 tire and have no rubbing issues at all.

Not your exact setup - but I don't think you'll have any issues.

- Matt
 

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Discussion Starter #3
and thats on the front?
 

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Keep in mind that SRT8s use a different offset than the R/T and SE/SXT due to using different spindles. This is why SRT8 wheels on stock R/Ts will cause rubbing, so in this case the SRT8 specs are irrelevant, unfortunately.

Subscribed as I'd like to run a similar setup and it's hard to get/find a solid answer. :)
 

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Discussion Starter #6 (Edited)
Keep in mind that SRT8s use a different offset than the R/T and SE/SXT due to using different spindles. This is why SRT8 wheels on stock R/Ts will cause rubbing, so in this case the SRT8 specs are irrelevant, unfortunately.

Subscribed as I'd like to run a similar setup and it's hard to get/find a solid answer. :)
Not sure if i follow that? R/T and SRT use the same knuckle and hubs. Maybe the thickness of the brake rotors are different causing them to fix the offset by changing the wheels offset to compensate.
I cant find the offset for the SRT 20x9 but I know the 20x8 R/T clads are a offset of +24
Also I assumed it was a brake clearance issue only with those rims not interchanging.
 

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Not sure if i follow that? R/T and SRT use the same knuckle and hubs. Maybe the thickness of the brake rotors are different causing them to fix the offset by changing the wheels offset to compensate.
I cant find the offset for the SRT 20x9 but I know the 20x8 R/T clads are a offset of +24
Also I assumed it was a brake clearance issue only with those rims not interchanging.
Not a brake clearance issue, the tire/wheel will rub on the upright if an SRT8 wheel is run on an R/T or SE/SXT without using a 3-5mm spacer. Spacers are pretty ghetto, IMO, and I won't run them considering how my car is used. So using SRT8 wheel specs for your R/T isn't going to work very well, but you could get close by knowing you need a spacer.
 

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Discussion Starter #8 (Edited)
well ok so if my theory is correct,, and if it is the case of a thicker rotor... then the srt wheel would need a higher offset number,,, say, maybe a offset of +26mm to compensate (i dont know what it exactly is just a guess). So putting a srt wheel on a rt will push the rim back 3mm (because the rotor is thinner) plus you have to account that a srt wheel is 1 inch wider,, or 1/2 inch deeper or closer to the inside of the car. So 1/2" is 12.7mm + 3mm = 15.7mm (this is a rough example only)

So you say a 3mm spacer fixes this rub?...so tech I could have enough info to figure out my answer using some math. Because by using a tire calculator I know the 20x9.5 with a 18 offset wheels I just bought for my car will set my wheels 13mm in the inside closer to my R/T compared to stock.
With some more info I can figue this out?
1- I need to know the actual offset of stock SRT wheels.
2- Exactly what size spacer do ppl use with srt on an rt car??? a 3mm or 5mm?
 

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well ok so if my theory is correct,, and if it is the case of a thicker rotor... then the srt wheel would need a higher offset number,,, say, maybe a offset of +26mm to compensate (i dont know what it exactly is just a guess). So putting a srt wheel on a rt will push the rim back 3mm (because the rotor is thinner) plus you have to account that a srt wheel is 1 inch wider,, or 1/2 inch deeper or closer to the inside of the car. So 1/2" is 12.7mm + 3mm = 15.7mm (this is a rough example only)

So you say a 3mm spacer fixes this rub?...so tech I could have enough info to figure out my answer using some math. Because by using a tire calculator I know the 20x9.5 with a 18 offset wheels I just bought for my car will set my wheels 13mm in the inside closer to my R/T compared to stock.
With some more info I can figue this out?
1- I need to know the actual offset of stock SRT wheels. 25.5mm
2- Exactly what size spacer do ppl use with srt on an rt car??? a 3mm or 5mm?
I don't know, however you'll need at least (2) 3mm spacers, so start with those and if the tires clear, you're done. If they still rub, stack the two spacers on one side and if that gets the clearance needed, order two more spacers for the other wheel.
 

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Discussion Starter #10
ok then,,, heres my math,,, think this is correct,,, so putting a srt wheel on a rt car will set the inside side of the wheel/tires 14.2mm closer to car,, and according to ppl here rubs, right? The set that I ordered and actually arrived today will set in 13mm closer then stock r/t so I'm super close to rubbing.
so thats a 1.2mm difference.
I might pick up a few spacers for the rear to get them out abit.
My main problem is i'm never worried about the rim rubbing but the tires,,, as soon as you mount the tires you cant return them.
Looks like Ill have to mount the tires and cross the fingers haha.
Whats the limit for spacers on our cars? Im not ganna ordered spacers untill i get em on the car,,, I also have a lowered car and want them under the wells as best as I can get.
 

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I think 6 mm is the maximum recommended, anymore than that puts too much stress on the studs.
 

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Discussion Starter #12 (Edited)
**UPDATE**
Ok just installed them and the verdict is they do fit,,, but with a 255/45/20 is they are very very close to touching the steering knucle/spindle at the top at the inside of the tire sidewall. I would recommend ppl to never go less then a 18mm offset or a wider tire or rim then 9.5 for the front. Unless you wanna get spacers.
 
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