245/40-18 Winter Tires - Fit ok?

[BlueWRXPride]

Someone at work has some lightly used X-Ice3 tires for sale in size 245/40-18. I know that's a little different than the stock 235/45-18 (2.3% difference in diameter) so that'll impact the speed accuracy, but would I have any fitment issues putting these on some aftermarket 18x8 wheels and using them for winter tires? I'm seeing some conflicting info on whether or not an 8" wheel is too narrow for a 245 tire.

 

[Snow Drift]

According to TireRack.com the 245/40-18 X-Ice Xi3 WILL fit, but 8" is the narrowest possible. https://www.tirerack.com/tires/tire...HR8XI3XL&vehicleSearch=false&fromCompare1=yes

However, 245 is really wide and have you confirmed that 18x8 rims fit the Model 3? The stockers are 8.5" and you may have clearance issues.

 

[BlueWRXPride]

When I enter the car information in TireRack, it says they are guaranteed to fit. If I use this calculator: Wheel Offset Calculator, then it says that

The top of the tire
to the fender well is:
0.3" Farther

The inner sidewall to the suspension and frame is:
0.05" Farther Away

The outer sidewall is:
0.35" Farther Out

 

[TurnFast]

Also just going to throw out there that you actually want your snow tires to be narrower vs wider.
If you're not planning on going through any significant snow probably doesn't matter.

 

[BlueWRXPride]

Yeah I realize that narrow is better. And yes I will be dealing with significant snow at times. But I didn't know if 10mm really would make a difference, and it would save me $400.

 

[Snow Drift]

Yeah I realize that narrow is better. And yes I will be dealing with significant snow at times. But I didn't know if 10mm really would make a difference, and it would save me $400.

It’s not ideal. My STI has 245 summers.