wheel fitment question
 

My current wheels/tires

Front: 18x8 et45 235/40/18
Rear: 18x8.5 et49 255/35/18

I am looking to get a set of winter wheel/tire

18x8 et45 225/40/18 all four wheels.

Any issue with this setup?
Thanks

The front tire is actually shorter by 8mm (or ~1.2%), and your tire is taller by 2mm. For wheel & tire offset clearance, you'll have even more space than before, so you're gonna be totally fine as far as rubbing is concerned.

You will also have a lot less rear grip, so watch out for that.

Thanks for the info. Is it actually better to have narrower winter tire then summer?

I would say so. The narrower width supposedly makes it easier for the tire to cut through water / slush / snow, and that has been consistent with my experience as well.

But the thing you really want to watch out for is how your front tires are only going 10mm narrower, while your rear tires are going 30mm narrower. Assuming that your current setup is OEM or close to what OEM is like, that means your car was engineered to drive and handle that way. And the way it is now is also most likely how you expect your car to drive. But with the rear tires getting so much narrower compared to before, and in comparison to front, it is going to be easier for you to lose rear traction (ie. oversteer / fish tail). And that is the thing I was asking you to pay special attention to. You rarely ever want to lose rear traction on the street, esp when you are in an RWD car.

My current setup is OEM and my car is RWD. I think square setup should be ok as I am not going to drive aggressively in winter.

Actually, as long as you don't turn off traction control, the car is gonna save you from getting into any sort of hairy situation.