Different size tires than stock - What effect one car
As long as you maintain the correct aspect ratio, you will not have to calibrate anything. The first number is just the width of the tire, the second, is a percentage, if that changes, then yes, you would need to calibrate your speedo.
As for going with a wider tire, when I went got mine, I noticed alot of tramlining/railroading (your tire will follow the contours of the road), its not a issue, just be aware of it, and don't be surprised







