I recently changed the Oil and filter on my wife's 2018 Trax ( using PEAK Full Synthetic 5W30 Dexos Approved Oil and STP 15,000 Mile Maximum Life Oil Filter ) and returned from a long road trip ( put approximately 3500 miles and drove for many hours at a time through 119 degree heat in the Arizona desert ) ... due to the nature of the drive, IE: Mileage and Heat, I'm considering changing the oil and filter although the mileage hasn't reached my usual OCI of 6,000 miles. I checked the oil upon returning home and it is still full but the oil appears to be pretty dark, almost black.... Thoughts?