as long as your overall wheel size is the same as stock, you will be fine. to find the overall wheel size, here is the formula:

[(tires width X profile (%) x 2) / 25.4] + rim size = overall wheel size

example: stock wheel size is 195 65 15

calculation: [(195 x 65% x 2) / 25.4] + 15 = 24.980315 inches

if you wanted an 18" rim, the tire size would be 225 40 18.

overall wheel size for an 18" rim is 25.086615 inches. (pretty close to stock)

hope this has been helpful.