I measured the tread on my hatch with 13,500 miles. The OEM Hankook 17" tires originally have 10/32 inch tread depth. I averaged 8/32 inch tread depth. Assuming replacement depth ~ 4/32 inch, I calculate a potential service life of around 40,500 miles.
If replaced at the legal limit of 2/32 inch depth, I potentially could go another 27,000 miles for a total of 67,500 miles. Other factors such as driving style, temperature, alignment, road surface, and speed will ultimately determine service life. Every individual will have different results, but measuring depth periodically and determining miles driven, will tell you how many miles you will obtain.
I also noted that the stock 17's have sufficient grip in warm, dry conditions; but they are possibly the worst I've driven on in snow and slushy winter weather. They don't like to start, stop, or turn in snow; equally insufficient on ice. Winter tires are in order for safe winter driving!