You need to be careful when changing the tire ratio for your car. The 225/60R18 was designed to fit for the height, width and tread depth.
I recommend you call a tire store and give them the year, make and model of your vehicle and ask what if any alternative sizes there are
〉 Answered on Mar 13th, 2015 by Amy Mattinat, Owner and Author at Auto Craftsmen Ltd
Normally you do not deviate from the original equipment size of tires. Each vehicle is different. You will have to go to a tire supplier and have them try one. I would not put them on without checking an actual tire on the car beforehand.
〉 Answered on Mar 13th, 2015 by Gail Dunn, Owner at Women's Automotive Connection