I will fit 20's tomorrow. I will send photo's of difference of 18's and 20's if I can post anywhere on this site.
I fitted 20 inch, it is confortable than I thought.
I reccomend 20's if you are thinking to fit 18's or 19's.
Not LS 400 but LS 430 can fit F 9J +37 245/35-20 R 9.5J +38 275/30-20 or 10J +37 285/30-20.
If 18's F 8.5J +33 245/45-18 R 9.5J +37 275/35-18.
I think best choice is 19's!