That's likely more the wheels, since I think we've determined on i4talk that the tire patch doesn't make a huge difference.

You won't have a configuration issue. You may want to get spacers depending on the look.

 

If you really drive a lot in snow, I would recommend to go with 17'', this is only tire size where you can use normal snow chains. on 18'' you are limited with some special expensive "narrow" versions due to limited space inside of the wheel arches. for 19/20'' no chains are possible, only snowsocks...
Tire width has limited impact on range, rim size is bigger impact factor.

 

17s are not offered in the US on the car OEM, and the manual doesn't offer the specs. Are they e40/e35 only? Or can you do them on the M50?

 

The OP doesn’t mention if he has M Sport brakes or not. Will 17 or even 18 inch wheels fit over the larger rotors and calipers if he has M Sport brakes?

 

OP here. i4 does have the m sport package with the 19” wheels and m calibers. The recommended 18” wheels on BMW site are M branded so I would assume they will fit. Agree I will need to have the correct wheel offset to clear the brakes.

So my question is since the tire contact size (patch) is the same between a the recommended 245/40r19 and 245/r18, will the range also be identical?

hoping the recommended 18” gets better range than the 19”

 

I expect the winter rubber will mean you may take a consumption hit from the winter tires.

 

In Europe :
i4 40 without Sport, 17 inch minimum
i4 40 with sport and i4M50, 18 inch minimum

 

I have the xDrive with M sport package and brakes (red calipers). Didn't have the car for the worst of last winter so didn't really get a feel for how it would perform on the stock all seasons. Today we had our first snow and it's pretty sure footed around corners but hitting the brakes was a bit scary.
I'd prefer to go with a narrower wheel than stock and I'd like to do a square setup so I can rotate each season.
However when I go to Tire Rack they only offer 245/45/r18 front and 255/45/r18 rear as an 18 inch option for the M sport brakes. If I say I don't have the M sport brakes I can get a 225/55/r18 square setup. My guess is this some sort of restriction from BMW for performance but I don't want to get the square setup and it doesn't fit for some reason.
Does anyone know if I would be ok or not getting the square setup?
My other concern is wheel weight placement. I know there will be tight clearance around the brakes for the 18 inch setup but if they don't think I have the M sport brakes they may not be a careful with the wheel weight placement and it might make contact. Had that issue with my last car (Mustang) though not from Tire Rack.

 

I'd prefer to go with a narrower wheel than stock and I'd like to do a square setup so I can rotate each season.
However when I go to Tire Rack they only offer 245/45/r18 front and 255/45/r18 rear as an 18 inch option for the M sport brakes. If I say I don't have the M sport brakes I can get a 225/55/r18 square setup.

I believe, you mean 225/45/R18 square setup. 225/55/R18 would be too big...

 

I actually don't have the MSport brakes (they could be removed from the package before a certain point), and I got 18" rims for my snow set.

For a while, the official BMW snow tire package was a square setup, but I dont know if that involved spacers, or something else would be involved, or if they just actually work with the MSport brakes. I asked and observed the installers test fit the rims when I had the tires mounted on them, so I do know they work without MSport brakes.

 

I have msport brakes and use 18” wheels for my winter set.

I bought them from BMW and got confirmation in advance they would fit. Then they were installed by the BMW dealer.

They work fine together

 

Hi There ~ Can you share which OEM rims / tire sizes you have? We have 2025 i4 xDrive40 MSport with the MSport brakes on its way and want to make sure that we get the correct 18" wheels/tires. TIA!

 

I also have the OEM 18" square setup with msport brakes. No fitment issues.

I'm an advocate for the square setup to allow front to rear rotations since the wear is so disproportionate.

 

How is your range with that package?