myvi come with 14 inch rim. Normal upgrade is go to 15inch rim with good street tires. Normally people avoid 16inch because the tire price close to 17 inch. Unless you want to spend abit extra on tire and don't mind performance drop. eg. poorer acceleration and braking power.. go ahead and upgrade to 16-17 inch tire..

With bigger rim like 16 or 17 inches, you will need lowering springs to pair with the looks, if not your car will look like 4x4 pickup truck. In return, this will cause your rear to rub if you fetch 5 people in your car, and depends on what brand of lowering springs u go for, it might be a harsher ride..