What's the best tire size for a Ford Fiesta ST?

I just purchased a Ford Fiesta ST and I'm looking to upgrade the tires. What is the best size to go with for optimal performance and handling?

I would recommend a size 205/40R17 tire. This will provide excellent grip and handling for your Fiesta ST.

I've been using a size 195/50R16 on my Fiesta ST and it has been working great for me. It offers a good balance of performance and comfort.

It really depends on your driving style and the roads you will be driving on. I personally prefer a size 215/40R17 for a sportier feel.