they now use stainless steel kingpins (from the early noughties???). It's the bronze bushes that wear the most, not the pins. Chrome plating was introduced by the after-market to prevent the old steel pins from rusting, which would lead to rapid bush wear, - hard chrome because ordinary chrome would peel off in use. Personally, I don't see any advantage of hard chromed pins over the stainless ones.
Fjemog
I don't know what they fit currently, but the early stainless KPs that the factory fitted were a pretty soft grade, so people found they still wore pretty quick. I don't have any personal experience, I went straight from mild steel to hardchrome. I was replacing the mild steels every 20k miles or so, I have 30k miles on my hardchromes with no discernible wear yet.
