So I'm about do my first oil change on my '15 focus st. My daily commute is not too long, about 32 miles round trip. Weekend trips can be anywhere from 0-100+. I essentially drive all highway and interstate miles. I don't drive too aggressively, though I do like to get into it now and then. It's a fun car to drive. Occasionally I take it past 100mph although very rarely. Also looking at an oci of around 8k. Looking for input on oils. Thinking about going with rp and sending a sample of it in for uoa on my next change. Has anyone had experience with rp high performance street? Not planning on getting it. Just wondering if it is worth the price and if it actually does anything. Why does it only recommend using it after the factory warranty is done? Sounds like good oil for my girlfriend's car. If it actually works. Thanks for all the help.