So I'm shopping for some 18 inch rims for the winter coming up. My stock rims are 18 inch. Tire size is 245/45-18, so would I have a problem just taking my stock rims out of the tires & swapping them for some 18x8.5 or 18x9.5? Or would the tires be too beefy?

 

I'm not exactly sure what you are doing. The OEM rims are 18" X 8.0", and that size will hold tires larger than the OEM 245/45VR18. What size winter tires are you thinking of using?

If you are thinking of mounting OEM size tires on an 18 X 8.5" rim, that can easily be done. But, to fit within the wheel well, an 18 X 9.5 rim would require a wider tire and lower profile than the OEM tires, and I don't think winter tires come in very low profiles.

Could you tell us once more exactly what you are thinking of doing, and maybe it will sink into my senile old head?

 

I just put a down payment on a set of Michelin X ice 3 winter tires for my stock 18" rims.
Tires are same size as OE, 245 45 18.
The X ice 3 are excellent winter tires.
I had a set on my Mazdaspeed 6.
They are great in snow, on ice and in the wet.
And are particularly quiet running for snows.

I plan to install my all seasons on a new set of aftermarket rims next spring.
I think a black chrome style.

 

You want narrower tires for winter, not wider.

 

Thanks for the info. Basically I was looking at a set where the front rims where 18x8.5 in the front & 18x9.5 in the back. But after hearing you're info I'll stay within the 18x8 or 18x8.5 rim size. My OEM wheels have never been driven on so I figured I could just swap the OEM rims this winter while taking off 20's

 

My new snows will be the same size as stock, not wider.
Narrower would be better, but narrower tires are not recommended on the stock rims.

 

225/50/18 is a perfectly acceptable alternative for a winter only tire.

 

This size is not a common size.

 

Yes, since you have the 18X8.0 OEM rims available, I would use those and mount winter tires on them. Winter tires tend to have taller, narrower profiles, so you absolutely would not want to change to a wider rim. Those OEM rims will hold the largest winter tires that would fit comfortably within the wheel wells. We don't want winter tires fitting too snugly within the wheel wells, as snow tends to accumulate and jam the wheel wells.