+12354 on the 19's

 

^^^LMFAO.. this guy! forget everything and stay with OEM's and just get AIR damn it!! Seriously please consider coilovers over springs for the long run and its a better investment in the future.

 

As someone stated, changing the wheel diameter won't lower the car, but it will alter the ground clearance.

As to looking "clean", that will depend on who you ask. Aesthetically speaking, I personally prefer the look of an evenly filled out wheel well, with some sidewall. 18's did it for me, but then I also took some other things into consideration.

I don't think you can go wrong with either, once you size things up correctly/tastefully.

 

how about some 19's with a stepped lip? this way the stepped lip takes from the diameter of the wheel which make them look smaller like 18's but have that real aggressive look to them

 

18s are a waste unless you are looking at performance or something. as far as looks 19 is the way to go. It will be hard to find 18's that look much better than the stock 18's which are pretty nice already.
Also, you will definitely need to lower your car. after spending so much in wheels you might as well go the extra yard and make the most out of it

 

I agree, even Lexus is spec'ing 19's with moderate lowering springs (via F-Sport wheels and F-Sport springs sold at the Lexus parts counter). Not radical territory at all.

 

19's and drop like its hot

 

Thumbs up for 19"s. Go for it...

 

If you have 17"s now, I think it would be a mistake to buy 18"s (for this car). I have the stock 18"s. If I had 17"s and was going to make a change, I would move right up to the 19"s. They'll look much better - especially after lowering.

Just look around at some of the CL pictures. You might agree that the IS's with 19"s and 20"s look incredible.