# Quick Offset Question



## thespr (Feb 21, 2016)

So I'm planning on buying new rims but don't want to go all out and get massive 18" rims because I don't have the funds up front to get all new tires as well, but I found a few 16" sets I love I'm just confused on width/offset.

The stock wheels I have now are 16x6.5 with a 40mm offset (I think). My tires I have are P215/60.

The rims I'm looking at are either 16x7, or 16x7.5.

My question is, when increasing wheel width, should I increase or decrease the offset to keep a flush look? Or will 40mm universally be alright for a flush look? 

Does 40mm offset stick out further than let's say.. 35mm offset?


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## Taxman (Aug 10, 2017)

1. They're offset inward, so 40mm is 1/5" closer to the car than 35mm. (or 35mm sticks out 5mm more than 40mm)

2. It's not about looking flush, it's about keeping suspension geometry correct. Don't change the offset more than 2-3mm unless you know what you're doing. Depending on the brakes/wheels, there might be clearance problems with different wheels, even with the same offset. I think in the Cruze world, the brake clearance problem is mainly on the 1st Gen diesels.


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## thespr (Feb 21, 2016)

Taxman said:


> 1. They're offset inward, so 40mm is 1/5" closer to the car than 35mm. (or 35mm sticks out 5mm more than 40mm)
> 
> 2. It's not about looking flush, it's about keeping suspension geometry correct. Don't change the offset more than 2-3mm unless you know what you're doing. Depending on the brakes/wheels, there might be clearance problems with different wheels, even with the same offset. I think in the Cruze world, the brake clearance problem is mainly on the 1st Gen diesels.


Thank you, so I'm assuming regardless of width, stay at about 38-42mm offset (40mm ideally), correct?

That clarifies things a lot, now tire size is the only other thing I'm confused about. Right now I have P215/60, do I HAVE to use those tires or can I use any other sizes? I think 235/55 would work since they end up with the same dimensions or whatever, but I'm not sure if I need to change tire size when increasing wheel width. May be safer to stick with what I know fits which is the P215/60 but just curious for when I have to get new tires.

Thank you!


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## Taxman (Aug 10, 2017)

Within reason, the same tires on wider wheels just corner a bit sharper from the better sidewall support. 

Wider tires, well, look at the overall width and diameter of the new tires vs the old tires, and see how much extra clearance you have around the old tires. Tire rubbing at full suspension jounce or full steering lock is annoying, rubbing under normal driving or hard car-tire contact at any time can be seriously bad.


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## thespr (Feb 21, 2016)

Taxman said:


> Within reason, the same tires on wider wheels just corner a bit sharper from the better sidewall support.
> 
> Wider tires, well, look at the overall width and diameter of the new tires vs the old tires, and see how much extra clearance you have around the old tires. Tire rubbing at full suspension jounce or full steering lock is annoying, rubbing under normal driving or hard car-tire contact at any time can be seriously bad.


This set of rims is 16x7, 40mm offset, but also indicates 5.6" wheel backspacing? I'm assuming all wheels have backspacing but this is the only set that explicitly says the length of the backspacing.

Is 5.6" too much?

Also can boresize be adjusted? My center bore is 56.6 but some sets of wheels have bore sizes of 70+, are those not going to work or can that fit somehow?

Edit: Found out I can get hubcentric rings for 73.1mm to 56.6mm and it will fit the new rims on. Pepboys is saying it will be $135 to install 4 new rims. Is that a fair estimate or?


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## Smurfenstein (Nov 16, 2011)

Personally, I would hold of until you can afford new tires and get 17s or 18s. 16s just look off to me.

As for all of your questions, backspacing will only help you dictate strut clearance, not caliper clearance. Our stock brakes are tiny, you shouldn't have an issue with aftermarket wheels in terms of clearance, keep the offset as close to 40 as you can and you will remain with a stock look. Lower the offset for a more flush look, you will be fine as long as you don't go lower than +30. For tires, running a 7" I would keep to the stock tire size, if you really want a wider tire, go with a 225, but there's no need.

As for hub bore, higher the number, bigger the hole. So if you have a smaller hub, you need a hubcentric ring to make up the gap, as you cant add metal to a wheel safely.


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