Tires and gear ratio

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CanRebel

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Very smart, I plan on going with a -12 offset. What happens when you deviate from stock offset ?

Was bored, so I checked. Says 17-21. some list it as 19. As @Dean2 mentioned above.
You should check for yourself and make sure you really want -12 , as he said above, that is a big change.
 
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da_garr99

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Was bored, so I checked. Says 17-21. some list it as 19. As @Dean2 mentioned above.
You should check for yourself and make sure you really want -12 , as he said above, that is a big change.
I'm definitely not going with a -12 offset. Would you reccomend a 0 or a +1 ? My wife bought me bushwacker fender flares and she has made it her mission to get them on lol. So I want to try and have the tires flush or a little inward, but don't want it to look super tucked in. My rims say 20×8j +19.05 on the back of them. Ideally I would like to go with a 9 inch wide rim but are a bit concerned with my suspension and uca. Thanks for the help
 
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da_garr99

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Minus 12 is 12 milimeters so about a half an inch. The stock offset was usually from positive 20 to 25 depending on the exact wheel package. That means you are moving the tires outboard about an inch and a half, which is quite a bit.
My rims are 20×8j 19.05. What would you reccomend for offset ? Want to go with 9 inch wide rim (don't know pros and cons to a wider rim) but concerned about uca and suspension
 
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Dean2

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Stock tires are 275/60/20 (33"), currently running 33×12.5 20. I want to either run 285/75/17 (33.8") or a 285/70/17 (32.7") falken wildpeak at3.

Going to an inch wider rim means it is 1/2" outside and in. Since you are at a -20 offset now on the stock rims a -8 would compensate fully for the extra 1/2". Based on your OEM stock tires being 275s, new tires 285, you are gaining less than a 1/2" in width, so the new tire is 11.2" versus stock at 10.8 and your existing tires at 12.5". So in effect you are going to a new tire that is 1.3" narrower than your existing tires. Personally, I would stay with the 8" or 8.5" rim and keep the stock offset.
 
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Dean2

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One final work of advice, a good tire or tire and rim shop should easily be able to get you into the right 17" rim using a factory or real close to factory offset of -16 to -20. Formula for tire with to Rim width is rim width x 1.33, so in this case ideal would be an 8.5" rim for the 285/75/17 tires, but 8" works too. Good thing about 17" tires is there is a way better selection and they are a whole bunch cheaper than 20 inch rubber. The biggest trick is to make sure nothing rubs and the rims clear your calipers, which on a 2009 they should as they came stock with 17s on some models.

Let us know what you end up with.
 
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Jeepwalker

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OP, Unless you have a particular style of aftermarket wheel in mind. But if not, are you open to a *stock* Ram 17" wheel? You might be able to find a good used set of take-off's on your local "used" listings (Facebook Marketplace/Craigslist ...or whatever is popular in your area). Perhaps a set that was removed years ago an owner now wants to get rid of. The benefit would be a good set of wheels for a lot less than aftermarkets. And around here (salt) aftermarket wheels don't typically hold up as well as OEM.

That's what I've done in the past on a few vehicles, when I wanted to get a better set of corrosion-free wheels. The previous owner of my Ram must have done that too by the looks of the build sheet.

Just a thought..
 
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da_garr99

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Going to an inch wider rim means it is 1/2" outside and in. Since you are at a -20 offset now on the stock rims a -8 would compensate fully for the extra 1/2". Based on your OEM stock tires being 275s, new tires 285, you are gaining less than a 1/2" in width, so the new tire is 11.2" versus stock at 10.8 and your existing tires at 12.5". So in effect you are going to a new tire that is 1.3" narrower than your existing tires. Personally, I would stay with the 8" rim and keep the stock offset.
That makes alot of sense, thank you for the help and very valuable knowledge.
 
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da_garr99

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OP, Unless you have a particular style of aftermarket wheel in mind. But if not, are you open to a *stock* Ram 17" wheel? You might be able to find a good used set of take-off's on your local "used" listings (Facebook Marketplace/Craigslist ...or whatever is popular in your area). Perhaps a set that was removed years ago an owner now wants to get rid of. The benefit would be a good set of wheels for a lot less than aftermarkets. And around here (salt) aftermarket wheels don't typically hold up as well as OEM.

That's what I've done in the past on a few vehicles, when I wanted to get a better set of corrosion-free wheels. The previous owner of my Ram must have done that too by the looks of the build sheet.

Just a thought..
I was looking at some fuel rims. Unfortunately where I am everybody thinks their beat up rims are worth 1k which is really stupid
 
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da_garr99

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One final work of advice, a good tire or tire and rim shop should easily be able to get you into the right 17" rim using a factory or real close to factory offset of -16 to -20. Formula for tire with to Rim width is rim width x 1.33, so in this case ideal would be an 8.5" rim for the 285/75/17 tires, but 8" works too. Good thing about 17" tires is there is a way better selection and they are a whole bunch cheaper than 20 inch rubber. The biggest trick is to make sure nothing rubs and the rims clear your calipers, which on a 2009 they should as they came stock with 17s on some models.

Let us know what you end up with.
Will definitely remember the rim formula. I would have loved to get some 2nd hand rims but people in BC price their rims stupid high and alot of tire shops out here are sold out on so much
 
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