I'd say that depends on what wheels you are going to use for your winter tires. If you are going to continue using the OEM wheels, you would want to use the same tire sizes as OEM - so 225/40R18 in front and 255/35R18 in the back. If you go aftermarket, you can do a "square" setup, with four identical wheels, and doing so will enable you to get the same size for all four tires.

 

I would recommend keeping factory size tires. Changing sizes could affect traction control and handling.

 

For real Winter, I recommend buying 4 factory front wheels (sometimes you can get the less desirable 5-spoke versions from the dealer super cheap, see link below), 4 OEM tire pressure monitors (cheapest on Amazon I think), and 4 dedicated Winter tires in the 225/40 size.

This will cause no issue whatsoever, and will give you better performance in all inclement weather.

The best part is that you can use them for longer because they are able to be rotated.

https://parts.lexus.com/p/Lexus_2018...TR5953130.html

 

You are going to have less width/traction/grip in the rear? How is that better performance?

 

You will have more traction/grip in the rear.

It's a universal rule that the skinnier the tire, the better snow traction. Have a look at the Rally car tires they use on the snow stages.

Wide tires are made for grip in cornering, the wider the tire the worse it will be in rain/snow necessarily.

 

+1, I have heard this as well. Lots of forum members here are using a square setup in winter. Should be fine.

The only "performance" downside is a little less dry grip at the rear when using the winter wheels. So technically, yes, you are making a sacrifice.