2015 MKS FWD: Hello I am Considering switching to 18" "?" from 19"x "8.5" to reduce weight and attain a smoother ride. I am trying to figure out what the weight and offset of potential wheels is. Please help. thank You
You probably won't be able to, because the brake calipers will more than likely hit the inside diameter of the wheels. That's why car manufacturers go to bigger wheels---to fit larger brakes inside of them.
I realize this thread is old but I suspect you could run 18" wheels on the MKS. 18s are standard on the Taurus which uses the same size brake calipers as the MKS. Mine was a 2010 model but I had the dealer swap the 19s that were standard on my MKS ecoboost for the 18s that were on a base model MKS at that time. The tires were Goodyear Comfortred 235/55/18. They rode beautifully and were whisper quiet. I do not know the offset but wheels from a base 2010-2012 MKS or even a 2010-2016 Taurus should be fine. I would certainly want to test-fit one first but I don't think they would rub on the brake calipers.