For our cars what would you say is a minimum Caliper to wheel Clearance for the front wheels?

It's only the front edge of the caliper that's close to the wheels, everything else has plenty of space.

 

I'm going to say 5mm because i'm overly cautious about wheel/tire related changes...but you will probably be able to get away with having as little as 2-3mm clearance. I don't know what the stock clearance is on our wheels! (i have stock 18s).

Do you know what the stock clearance was vs. the new wheel clearance?

 

3mm its what brembo kits recommend so hopefully you got that

 

I checked with a couple shops and they said 2mm minimum is safe. When they first put on the wheels and tried to back the car it shaved the front edge of the caliper.

I'm getting 3 mm spacers since they are still safe with oem studs and will shave that edge of the caliper when I repaint it later this year. I never thought to check the clearance prior to install because I assumed since it was a OEM lexus wheel it would be fine, but I guess the ES calipers are much smaller.

 

These guys have a handy calculator that may be helpful if you can chase down the variables:

http://www.tceperformanceproducts.co...per-clearance/

I never measured it but the clearance on my '18 STI was very small. I would guess 2mm, 3mm max which seems to jive with some of the comments above given it had giant, 6 piston brembos.